Production of ethylene with nanowire catalysts

ABSTRACT

Methods for producing ethylene using nanowires as heterogeneous catalysts are provided. The method includes, for example, an oxidative coupling of methane catalyzed by nanowires to provide ethylene.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims the benefit under 35 U.S.C. §119(e) ofU.S. Provisional Patent Application No. 61/347,774 filed on May 24, 2010and U.S. Provisional Patent Application No. 61/425,631 filed on Dec. 21,2010 both of which are incorporated herein by reference in theirentireties.

BACKGROUND

Technical Field

This invention is generally related to novel nanowire catalysts and,more specifically, to nanowires useful as heterogeneous catalysts in avariety of catalytic reactions, such as the oxidative coupling ofmethane to ethylene.

Description of the Related Art

Catalysis is the process in which the rate of a chemical reaction iseither increased or decreased by means of a catalyst. Positive catalystsincrease the speed of a chemical reaction, while negative catalysts slowit down. Substances that increase the activity of a catalyst arereferred to as promoters or activators, and substances that deactivate acatalyst are referred to as catalytic poisons or deactivators. Unlikeother reagents, a catalyst is not consumed by the chemical reaction, butinstead participates in multiple chemical transformations. In the caseof positive catalysts, the catalytic reaction generally has a lowerrate-limiting free energy change to the transition state than thecorresponding uncatalyzed reaction, resulting in an increased reactionrate at the same temperature. Thus, at a given temperature, a positivecatalyst tends to increase the yield of desired product while decreasingthe yield of undesired side products. Although catalysts are notconsumed by the reaction itself, they may be inhibited, deactivated ordestroyed by secondary processes, resulting in loss of catalyticactivity.

Catalysts are generally characterized as either heterogeneous orhomogeneous. Heterogeneous catalysts exist in a different phase than thereactants (e.g. a solid metal catalyst and gas phase reactants), and thecatalytic reaction generally occurs on the surface of the heterogeneouscatalyst. Thus, for the catalytic reaction to occur, the reactants mustdiffuse to and/or adsorb onto the catalyst surface. This transport andadsorption of reactants is often the rate limiting step in aheterogeneous catalysis reaction. Heterogeneous catalysts are alsogenerally easily separable from the reaction mixture by commontechniques such as filtration or distillation.

In contrast to a heterogeneous catalyst, a homogenous catalyst exists inthe same phase as the reactants (e.g., a soluble organometallic catalystand solvent-dissolved reactants). Accordingly, reactions catalyzed by ahomogeneous catalyst are controlled by different kinetics than aheterogeneously catalyzed reaction. In addition, homogeneous catalystscan be difficult to separate from the reaction mixture.

While catalysis is involved in any number of technologies, oneparticular area of importance is the petrochemical industry. At thefoundation of the modern petrochemical industry is the energy-intensiveendothermic steam cracking of crude oil. Cracking is used to producenearly all the fundamental chemical intermediates in use today. Theamount of oil used for cracking and the volume of green house gases(GHG) emitted in the process are quite large: cracking consumes nearly10% of the total oil extracted globally and produces 200M metric tons ofCO₂ equivalent every year (Ren, T, Patel, M. Res. Conserv. Recycl.53:513, 2009). There remains a significant need in this field for newtechnology directed to the conversion of unreactive petrochemicalfeedstocks (e.g. paraffins, methane, ethane, etc.) into reactivechemical intermediates (e.g. olefins), particularly with regard tohighly selective heterogeneous catalysts for the direct oxidation ofhydrocarbons.

While there are multistep paths to convert methane to certain specificchemicals using first; high temperature steam reforming to syngas (amixture of H₂ and CO), followed by stochiometry adjustment andconversion to either methanol or, via the Fischer-Tropsch (F-T)synthesis, to liquid hydrocarbon fuels such as diesel or gasoline, thisdoes not allow for the formation of certain high value chemicalintermediates. This multi-step indirect method also requires a largecapital investment in facilities and is expensive to operate, in partdue to the energy intensive endothermic reforming step. (For instance,in methane reforming, nearly 40% of methane is consumed as fuel for thereaction.) It is also inefficient in that a substantial part of thecarbon fed into the process ends up as the GHG CO₂, both directly fromthe reaction and indirectly by burning fossil fuels to heat thereaction. Thus, to better exploit the natural gas resource, directmethods that are more efficient, economical and environmentallyresponsible are required.

One of the reactions for direct natural gas activation and itsconversion into a useful high value chemical, is the oxidative couplingof methane (“OCM”) to ethylene: 2CH₄+O₂→C₂H₄+2H₂O, See, e.g., Zhang, Q.,Journal of Natural Gas Chem., 12:81, 2003; Olah, G. “HydrocarbonChemistry”, Ed. 2, John Wiley & Sons (2003). This reaction is exothermic(ΔH=−67 kcals/mole) and has only been shown to occur at very hightemperatures (>700° C.). Although the detailed reaction mechanism is notfully characterized, experimental evidence suggests that free radicalchemistry is involved. (Lunsford, J. Chem. Soc., Chem. Comm., 1991; H.Lunsford, Angew. Chem., Int. Ed. Engl., 34:970, 1995). In the reaction,methane (CH₄) is activated on the catalyst surface, forming methylradicals which then couple in the gas phase to form ethane (C₂H₆),followed by dehydrogenation to ethylene (C₂H₄). Several catalysts haveshown activity for OCM, including various forms of iron oxide, V₂O₅,MoO₃, CO₃O₄, Pt—Rh, Li/ZrO₂, Ag—Au, Au/CO₃O₄, Co/Mn, CeO₂, MgO, La₂O₃,Mn₃O₄, Na₂WO₄, MnO, ZnO, and combinations thereof, on various supports.A number of doping elements have also proven to be useful in combinationwith the above catalysts.

Since the OCM reaction was first reported over thirty years ago, it hasbeen the target of intense scientific and commercial interest, but thefundamental limitations of the conventional approach to C—H bondactivation appear to limit the yield of this attractive reaction.Specifically, numerous publications from industrial and academic labshave consistently demonstrated characteristic performance of highselectivity at low conversion of methane, or low selectivity at highconversion (J. A. Labinger, Cat. Lett., 1:371, 1988). Limited by thisconversion/selectivity threshold, no OCM catalyst has been able toexceed 20-25% combined C₂ yield (i.e. ethane and ethylene), and all suchyields are reported at extremely high temperatures (>800 C). This lackof progress with conventional heterogeneous catalysts and reactorsduring the last third of a century suggests that conventional approacheshave reached the limit of their performance.

In this regard, it is believed that the low yield of desired products(i.e. C₂H₄ and C₂H₆) is caused by the unique homogeneous/heterogeneousnature of the reaction. Specifically, due to the high reactiontemperature, a majority of methyl radicals escape the catalyst surfaceand enter the gas phase. There, in the presence of oxygen and hydrogen,multiple side reactions are known to take place (J. A. Labinger, Cat.Lett., 1:371, 1988). The non-selective over-oxidation of hydrocarbons toCO and CO₂ (e.g., complete oxidation) is the principal competing fastside reaction. Other undesirable products (e.g. methanol, formaldehyde)have also been observed and rapidly react to form CO and CO₂.

In order to dramatically increase the yield of OCM, a catalyst optimizedfor the activation of the C—H bond of methane at lower temperatures(e.g. 500-900° C.) is required. While the above discussion has focusedon the OCM reaction, numerous other catalytic reactions (as discussed ingreater detail below) would significantly benefit from catalyticoptimization. Accordingly, there remains a need in the art for improvedcatalysts and, more specifically, a need for novel approaches tocatalyst design for improving the yield of, for example, the OCMreaction and other catalyzed reactions. The present invention fulfillsthese needs and provides further related advantages.

BRIEF SUMMARY

In brief, nanowires and related methods are disclosed. In oneembodiment, the disclosure provides a catalyst comprising an inorganiccatalytic polycrystalline nanowire, the nanowire having a ratio ofeffective length to actual length of less than one and an aspect ratioof greater than ten as measured by TEM in bright field mode at 5 keV,wherein the nanowire comprises one or more elements from any of Groups 1through 7, lanthanides, actinides or combinations thereof.

In another embodiment, the disclosure provides a catalytic materialcomprising a plurality of inorganic catalytic polycrystalline nanowires,the plurality of nanowires having a ratio of average effective length toaverage actual length of less than one and an average aspect ratio ofgreater than ten as measured by TEM in bright field mode at 5 keV,wherein the plurality of nanowires comprises one or more elements fromany of Groups 1 through 7, lanthanides, actinides or combinationsthereof.

In yet another embodiment, a method for preparing inorganic catalyticpolycrystalline nanowires is provided, the nanowires each having a ratioof effective length to actual length of less than one and an aspectratio of greater than ten as measured by TEM in bright field mode at 5keV, wherein the nanowires each comprise one or more elements selectedfrom Groups 1 through 7, lanthanides, actinides or combinations thereof.The method comprises:

admixing (A) with a mixture comprising (B) and (C);

admixing (B) with a mixture comprising (A) and (C); or

admixing (C) with a mixture comprising (A) and (B)

to obtain a mixture comprising (A), (B) and (C), wherein (A), (B), and(C) comprise, respectively:

(A) a biological template;

(B) one or more salts comprising one or more metal elements from any ofGroups 1 through 7, lanthanides, actinides or combinations thereof; and

(C) one or more anion precursors.

In another embodiment, a process for the preparation of ethylene frommethane comprising contacting a mixture comprising oxygen and methane ata temperature below 900° C. with a catalyst comprising one or moreinorganic catalytic nanowires is provided.

In yet another embodiment, the present disclosure provides for the useof a catalytic nanowire in a catalytic reaction. The nanowire may haveany composition or morphology, for example the nanowire may comprise oneor more elements from any of Groups 1 through 7, lanthanides, actinidesor combinations thereof, and the nanowire may optionally be apolycrystalline nanowire, the nanowire having a ratio of effectivelength to actual length of less than one and an aspect ratio of greaterthan ten as measured by TEM in bright field mode at 5 keV.

In another embodiment, the present disclosure provides a method forpreparing a downstream product of ethylene, the method comprisingconverting ethylene to a downstream product of ethylene, wherein theethylene has been prepared via a reaction employing a catalyticnanowire. In certain embodiments, the nanowire comprises one or moreelements from any of Groups 1 through 7, lanthanides, actinides orcombinations thereof, and the nanowire may optionally be apolycrystalline nanowire, the nanowire having a ratio of effectivelength to actual length of less than one and an aspect ratio of greaterthan ten as measured by TEM in bright field mode at 5 keV.

In another embodiment, the disclosure provides an inorganic nanowirecomprising one or more metal elements from any of Groups 1 through 7,lanthanides, actinides or combinations thereof, and a dopant comprisinga metal element, a semi-metal element, a non-metal element orcombinations thereof.

In another embodiment, the disclosure provides a method for preparing ametal oxide nanowire comprising a plurality of metal oxides(M_(x)O_(y)), the method comprising:

a) providing a solution comprising a plurality of biological templates;

(b) introducing at least one metal ion and at least one anion to thesolution under conditions and for a time sufficient to allow fornucleation and growth of a nanowire comprising a plurality of metalsalts (M_(m)X_(n)Z_(p)) on the template; and

(c) converting the nanowire (M_(m)X_(n)Z_(p)) to a metal oxide nanowirecomprising a plurality of metal oxides (M_(x)O_(y)),

wherein:

M is, at each occurrence, independently a metal element from any ofGroups 1 through 7, lanthanides or actinides;

X is, at each occurrence, independently hydroxides, carbonates,bicarbonates, phosphates, hydrogenphosphates, dihydrogenphosphates,sulfates, nitrates or oxalates;

Z is O;

n, m, x and y are each independently a number from 1 to 100; and

p is a number from 0 to 100.

In another embodiment, the disclosure provides a method for preparing ametal oxide nanowire, the method comprising:

(a) providing a solution comprising a plurality of biological templates;and

(b) introducing a compound comprising a metal to the solution underconditions and for a time sufficient to allow for nucleation and growthof a nanowire (M_(m)Y_(n)) on the template;

wherein:

M is a metal element from any of Groups 1 through 7, lanthanides oractinides;

Y is O,

n and m are each independently a number from 1 to 100.

In another embodiment, the disclosure provides a method for preparingmetal oxide nanowires in a core/shell structure, the method comprising:

(a) providing a solution comprising a plurality of biological templates;

(b) introducing a first metal ion and a first anion to the solutionunder conditions and for a time sufficient to allow for nucleation andgrowth of a first nanowire (M1_(m1)X1_(n1)Z_(p1)) on the template; and

(c) introducing a second metal ion and optionally a second anion to thesolution under conditions and for a time sufficient to allow fornucleation and growth of a second nanowire (M2_(m2)X2_(n2)Z_(p2)) on thefirst nanowire (M1_(m1)X1_(n1)Z_(p1));

(d) converting the first nanowire (M1_(m1)X1_(n1)Z_(p1)) and the secondnanowire (M2_(m2)X2_(n2)Z_(p2)) to respective metal oxide nanowires(M1_(x1)O_(y1)) and (M2_(x2)O_(y2)).

wherein:

M1 and M2 are the same or different and independently selected from ametal element from any of Groups 1 through 7, lanthanides or actinides;

X1 and X2 are the same or different and independently hydroxides,carbonates, bicarbonates, phosphates, hydrogenphosphates,dihydrogenphosphates, sulfates, nitrates or oxalates;

Z is O;

n1, m1, n2, m2, x1, y1, x2 and y2 are each independently a number from 1to 100; and

p1 and p2 are each independently a number from 0 to 100.

In yet another embodiment, the present disclosure provides a method forthe preparation of a downstream product of ethylene, the methodcomprising converting methane into ethylene in the presence of acatalytic nanowire and further oligomerizing the ethylene to prepare adownstream product of ethylene. In certain embodiments, the nanowirecomprises one or more elements from any of Groups 1 through 7,lanthanides, actinides or combinations thereof, and the nanowire mayoptionally be a polycrystalline nanowire, the nanowire having a ratio ofeffective length to actual length of less than one and an aspect ratioof greater than ten as measured by TEM in bright field mode at 5 keV.

These and other aspects of the invention will be apparent upon referenceto the following detailed description. To this end, various referencesare set forth herein which describe in more detail certain backgroundinformation, procedures, compounds and/or compositions, and are eachhereby incorporated by reference in their entirety.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

In the drawings, the sizes and relative positions of elements in thedrawings are not necessarily drawn to scale. For example, the variouselements and angles are not drawn to scale, and some of these elementsare arbitrarily enlarged and positioned to improve drawing legibility.Further, the particular shapes of the elements as drawn are not intendedto convey any information regarding the actual shape of the particularelements, and have been selected solely for ease of recognition in thedrawings.

FIG. 1 schematically depicts a first part of an OCM reaction at thesurface of a metal oxide catalyst.

FIG. 2 shows a high throughput work flow for synthetically generatingand testing libraries of nanowires.

FIGS. 3A and 3B illustrate a nanowire in one embodiment.

FIGS. 4A and 4B illustrate a nanowire in a different embodiment.

FIGS. 5A and 5B illustrate a plurality of nanowires.

FIG. 6 illustrates a filamentous bacteriophage.

FIG. 7 is a flow chart of a nucleation process for forming a metal oxidenanowire.

FIG. 8 is a flow chart of a sequential nucleation process for forming ananowire in a core/shell configuration.

FIG. 9 schematically depicts a carbon dioxide reforming reaction on acatalytic surface.

FIG. 10 is a flow chart for data collection and processing in evaluatingcatalytic performance.

FIG. 11 illustrates a number of downstream products of ethylene.

FIG. 12 depicts a representative process for preparing a lithium dopedMgO nanowire.

FIG. 13 presents the X-ray diffraction patterns of Mg(OH)₂ nanowires andMgO nanowires.

FIG. 14 shows a number of MgO nanowires each synthesized in the presenceof a different phage sequence.

FIG. 15 depicts a representative process for growing a core/shellstructure of ZrO₂/La₂O₃ nanowires with Strontium dopant.

FIG. 16 is a gas chromatograph showing the formation of OCM products at700° C. when passed over a Sr doped La₂O₃ nanowire.

FIGS. 17A-17C are graphs showing methane conversion, C2 selectivity, andC2 yield, in an OCM reaction catalyzed by Sr doped La₂O₃ nanowires vs.the corresponding bulk material in the same reaction temperature range.

FIGS. 18A-18B are graphs showing the comparative results of C2selectivities in an OCM reaction catalyzed by Sr doped La₂O₃ nanowirecatalysts prepared by different synthetic conditions.

FIG. 19 is a graph comparing ethane and propane conversions in ODHreactions catalyzed by either Li doped MgO phage-based nanowires or Lidoped MgO bulk catalyst.

FIG. 20 is a TEM image showing La₂O₃ nanowires prepared undernon-template-directed conditions.

FIG. 21 depicts OCM and ethylene oligomerization modules.

FIG. 22 shows methane conversion, C2 selectivity and C2 yield in areaction catalyzed by a representative nanowire at a CH₄/O₂ ratio of 4.

FIG. 23 shows methane conversion, C2 selectivity and C2 yield in areaction catalyzed by a representative nanowire at a CH₄/O₂ ratio of5.5.

FIG. 24 is a graph showing methane conversion, C2 selectivity and C2yield in a reaction catalyzed by Mg/Na doped La₂O₃ nanowires.

DETAILED DESCRIPTION OF THE INVENTION

In the following description, certain specific details are set forth inorder to provide a thorough understanding of various embodiments.However, one skilled in the art will understand that the invention maybe practiced without these details. In other instances, well-knownstructures have not been shown or described in detail to avoidunnecessarily obscuring descriptions of the embodiments. Unless thecontext requires otherwise, throughout the specification and claimswhich follow, the word “comprise” and variations thereof, such as,“comprises” and “comprising” are to be construed in an open, inclusivesense, that is, as “including, but not limited to.” Further, headingsprovided herein are for convenience only and do not interpret the scopeor meaning of the claimed invention.

Reference throughout this specification to “one embodiment” or “anembodiment” means that a particular feature, structure or characteristicdescribed in connection with the embodiment is included in at least oneembodiment. Thus, the appearances of the phrases “in one embodiment” or“in an embodiment” in various places throughout this specification arenot necessarily all referring to the same embodiment. Furthermore, theparticular features, structures, or characteristics may be combined inany suitable manner in one or more embodiments. Also, as used in thisspecification and the appended claims, the singular forms “a,” “an,” and“the” include plural referents unless the content clearly dictatesotherwise. It should also be noted that the term “or” is generallyemployed in its sense including “and/or” unless the content clearlydictates otherwise.

As discussed above, heterogeneous catalysis takes place between severalphases. Generally, the catalyst is a solid, the reactants are gases orliquids and the products are gases or liquids. Thus, a heterogeneouscatalyst provides a surface that has multiple active sites foradsorption of one more gas or liquid reactants. Once adsorbed, certainbonds within the reactant molecules are weakened and dissociate,creating reactive fragments of the reactants, e.g., in free radicalforms. One or more products are generated as new bonds between theresulting reactive fragments form, in part, due to their proximity toeach other on the catalytic surface.

As an example, FIG. 1 shows schematically the first part of an OCMreaction that takes place on the surface of a metal oxide catalyst 10which is followed by methyl radical coupling in the gas phase. A crystallattice structure of metal atoms 14 and oxygen atoms 20 are shown, withan optional dopant 24 incorporated into the lattice structure. In thisreaction, a methane molecule 28 comes into contact with an active site(e.g., surface oxygen 30) and becomes activated when a hydrogen atom 34dissociates from the methane molecule 28. As a result, a methyl radical40 is generated on or near the catalytic surface. Two methyl radicalsthus generated can couple in the gas phase to create ethane and/orethylene, which are collectively referred to as the “C2” couplingproducts.

It is generally recognized that the catalytic properties of a catalyststrongly correlate to its surface morphology. Typically, the surfacemorphology can be defined by geometric parameters such as: (1) thenumber of surface atoms (e.g., the surface oxygen of FIG. 1) thatcoordinate to the reactant; and (2) the degree of coordinativeunsaturation of the surface atoms, which is the coordination number ofthe surface atoms with their neighboring atoms. For example, thereactivity of a surface atom decreases with decreasing coordinativeunsaturation. For example, for the dense surfaces of a face-centeredcrystal, a surface atom with 9 surface atom neighbors will have adifferent reactivity than one with 8 neighbors. Additional surfacecharacteristics that may contribute to the catalytic properties include,for example, crystal dimensions, lattice distortion, surfacereconstructions, defects, grain boundaries, and the like. See, e.g., VanSanten R. A. et al New Trends in Materials Chemistry 345-363 (1997).

Catalysts in nano-size dimensions have substantially increased surfaceareas compared to their counterpart bulk materials. The catalyticproperties are expected to be enhanced as more surface active sites areexposed to the reactants. Typically in traditional preparations, atop-down approach (e.g., milling) is adopted to reduce the size of thebulk material. However, the surface morphologies of such catalystsremain largely the same as those of the parent bulk material.

Various embodiments described herein are directed to nanowires withcontrollable or tunable surface morphologies. In particular, nanowiressynthesized by a “bottom up” approach, by which inorganicpolycrystalline nanowires are nucleated from solution phase in thepresence of a template, e.g., a linear or anisotropic shaped biologicaltemplate. By varying the synthetic conditions, nanowires havingdifferent compositions and/or different surface morphologies aregenerated.

In contrast to a bulk catalyst of a given elemental composition, whichis likely to have a particular corresponding surface morphology, diversenanowires with different surface morphologies can be generated despitehaving the same elemental composition. In this way, morphologicallydiverse nanowires can be created and screened according to theircatalytic activity and performance parameters in any given catalyticreaction. Advantageously, the nanowires disclosed herein and methods ofproducing the same have general applicability to a wide variety ofheterogeneous catalyses, including without limitation: oxidativecoupling of methane (e.g., FIG. 1), oxidative dehydrogenation of alkanesto their corresponding alkenes, selective oxidation of alkanes toalkenes and alkynes, oxidation of carbon monoxide, dry reforming ofmethane, selective oxidation of aromatics, Fischer-Tropsch reaction,hydrocarbon cracking and the like.

FIG. 2 schematically shows a high throughput work flow for syntheticallygenerating libraries of morphologically or compositionally diversenanowires and screening for their catalytic properties. An initial phaseof the work flow involves a primary screening, which is designed tobroadly and efficiently screen a large and diverse set of nanowires thatlogically could perform the desired catalytic transformation. Forexample, certain doped bulk metal oxides (e.g., Li/MgO and Sr/La₂O₃) areknown catalysts for the OCM reaction. Therefore, nanowires of variousmetal oxide compositions and/or surface morphologies can be prepared andevaluated for their catalytic performances in an OCM reaction.

More specifically, the work flow 100 begins with designing syntheticexperiments based on solution phase template formations (block 110). Thesynthesis, subsequent treatments and screenings can be manual orautomated. As will be discussed in more detail herein, by varying thesynthetic conditions, nanowires can be prepared with various surfacemorphologies and/or compositions in respective microwells (block 114).The nanowires are subsequently calcined and then optionally doped (block120). Optionally, the doped and calcined nanowires are further mixedwith a catalyst support (block 122). Beyond the optional support step,all subsequent steps are carried out in a “wafer” format, in whichnanowire catalysts are deposited in a quartz wafer that has been etchedto create an ordered array of microwells. Each microwell is aself-contained reactor, in which independently variable processingconditions can be designed to include, without limitation, respectivechoices of elemental compositions, catalyst support, reactionprecursors, templates, reaction durations, pH values, temperatures,ratio between reactants, gas flows, and calcining conditions (block124). Due to design contrasts of some wafers, in some embodimentscalcining and other temperature variables are identical in allmicrowells. A wafer map 130 can be created to correlate the processingconditions to the nanowire in each microwell. A library of diversenanowires can be generated in which each library member corresponds to aparticular set of processing conditions and corresponding compositionaland/or morphological characteristics.

Nanowires obtained under various synthetic conditions are thereafterdeposited in respective microwells of a wafer (140) for evaluating theirrespective catalytic properties in a given reaction (blocks 132 and134). The catalytic performance of each library member can be screenedserially by several known primary screening technologies, includingscanning mass spectroscopy (SMS) (Symyx Technologies Inc., Santa Clara,Calif.). The screening process is fully automated, and the SMS tool candetermine if a nanowire is catalytically active or not, as well as itsrelative strength as a catalyst at a particular temperature. Typically,the wafer is placed on a motion control stage capable of positioning asingle well below a probe that flows the feed of the starting materialover the nanowire surface and removes reaction products to a massspectrometer and/or other detector technologies (blocks 134 and 140).The individual nanowire is heated to a preset reaction temperature,e.g., using a CO₂ IR laser from the backside of the quartz wafer and anIR camera to monitor temperature and a preset mixture of reactant gases.The SMS tool collects data with regard to the consumption of thereactant(s) and the generation of the product(s) of the catalyticreaction in each well (block 144), and at each temperature and flowrate.

The SMS data obtained as described above provide information on relativecatalytic properties among all the library members (block 150). In orderto obtain more quantitative data on the catalytic properties of thenanowires, possible hits that meet certain criteria are subjected to asecondary screening (block 154). Typically, secondary screeningtechnologies include a single, or alternatively multiple channelfixed-bed or fluidized bed reactors (as described in more detailherein). In parallel reactor systems or multi-channel fixed-bed reactorsystem, a single feed system supplies reactants to a set of flowrestrictors. The flow restrictors divide the flows evenly among parallelreactors. Care is taken to achieve uniform reaction temperature betweenthe reactors such that the various nanowires can be differentiatedsolely based on their catalytic performances. The secondary screeningallows for accurate determination of catalytic properties such asselectivity, yield and conversion.(block 160). These results serve as afeedback for designing further nanowire libraries. Additionaldescription of SMS tools in a combinatorial approach for discoveringcatalysts can be found in, e.g., Bergh, S. et al. Topics in Catalysts23:1-4, 2003.

Thus, in accordance with various embodiments described herein,compositional and morphologically diverse nanowires can be rationallysynthesized to meet catalytic performance criteria. These and otheraspects of the present disclosure are described in more detail below.

Definitions

As used herein, and unless the context dictates otherwise, the followingterms have the meanings as specified below.

“Catalyst” means a substance which alters the rate of a chemicalreaction. A catalyst may either increase the chemical reaction rate(i.e. a “positive catalyst”) or decrease the reaction rate (i.e. a“negative catalyst”). Catalysts participate in a reaction in a cyclicfashion such that the catalyst is cyclically regenerated. “Catalytic”means having the properties of a catalyst.

“Nanoparticle” means a particle having at least one diameter on theorder of nanometers (e.g. between about 1 and 100 nanometers).

“Nanowire” means a nanowire structure having at least one diameter onthe order of nanometers (e.g. between about 1 and 100 nanometers) and anaspect ratio greater than 10:1. The “aspect ratio” of a nanowire is theratio of the actual length (L) of the nanowire to the diameter (D) ofthe nanowire. Aspect ratio is expressed as L:D.

“Polycrystalline nanowire” means a nanowire having multiple crystaldomains. Polycrystalline nanowires generally have different morphologies(e.g. bent vs. straight) as compared to the corresponding“single-crystalline” nanowires.

“Effective length” of a nanowire means the shortest distance between thetwo distal ends of a nanowire as measured by transmission electronmicroscopy (TEM) in bright field mode at 5 keV. “Average effectivelength” refers to the average of the effective lengths of individualnanowires within a plurality of nanowires.

“Actual length” of a nanowire means the distance between the two distalends of a nanowire as traced through the backbone of the nanowire asmeasured by TEM in bright field mode at 5 keV. “Average actual length”refers to the average of the actual lengths of individual nanowireswithin a plurality of nanowires.

The “diameter” of a nanowire is measured in an axis perpendicular to theaxis of the nanowire's actual length (i.e. perpendicular to thenanowires backbone). The diameter of a nanowire will vary from narrow towide as measured at different points along the nanowire backbone. Asused herein, the diameter of a nanowire is the most prevalent (i.e. themode) diameter.

The “ratio of effective length to actual length” is determined bydividing the effective length by the actual length. A nanowire having a“bent morphology” will have a ratio of effective length to actual lengthof less than one as described in more detail herein. A straight nanowirewill have a ratio of effective length to actual length equal to one asdescribed in more detail herein.

“Inorganic” means a substance comprising a metal element. Typically, aninorganic can be one or more metals in its elemental state, or morepreferably, a compound formed by a metal ion (M^(n+), wherein n 1, 2, 3,4, 5, 6 or 7) and an anion (X^(m−), m is 1, 2, 3 or 4) which balance andneutralize the positive charges of the metal ion through electrostaticinteractions. Non-limiting examples of inorganic compounds includeoxides, hydroxides, halides, nitrates, sulfates, carbonates, acetates,oxalates, and combinations thereof, of metal elements. Othernon-limiting examples of inorganic compounds include Li₂CO₃, LiOH, Li₂O,LiCl, LiBr, LiI, Li₂C₂O₄, Li₂SO₄, Na₂CO₃, NaOH, Na₂O, NaCl, NaBr, NaI,Na₂C₂O₄, Na₂SO₄, K₂CO₃, KOH, K₂O, KCl, KBr, KI, K₂C₂O₄, K₂SO₄, CsCO₃,CsOH, Cs₂O, CsCl, CsBr, CsI, CsC₂O₄, CsSO₄, Be(OH)₂, BeCO₃, BeO, BeCl₂,BeBr₂, BeI₂, BeC₂O₄. BeSO₄, Mg(OH)₂, MgCO₃, MgO, MgCl₂, MgBr₂, MgI₂,MgC₂O₄. MgSO₄, Ca(OH)₂, CaO, CaCl₂, CaBr₂, CaI₂, Ca(OH)₂, CaC₂O₄, CaSO₄,Y₂O₃, Y₂(CO3)₃, Y(OH)₃, YCl₃, YBr₃, YI₃, Y₂(C₂O4)₃, Y₂(SO4)₃, Zr(OH)₄,ZrO(OH)₂, ZrO2, ZrCl₄, ZrBr₄, ZrI₄, Zr(C₂O₄)₂, Zr(SO₄)₂, Ti(OH)₄,TiO(OH)₂, TiO2, TiCl₄, TiBr₄, TiI₄, Ti(C₂O₄)₂, Ti(SO₄)₂, BaO, Ba(OH)₂,BaCO₃, BaCl₂, BaBr₂, BaI₂, BaC₂O₄, BaSO₄, La(OH)₃, La₂O₃, LaCl₃, LaBr₃,LaI₃, La₂(C₂O₄)₃, La₂(SO₄)₃, Ce(OH)₄, CeO₂, Ce₂O₃, CeCl₄, CeBr₄, CeI₄,Ce(C₂O₄)₂, Ce(SO₄)₂, ThO₂, ThCl₄, ThBr₄, ThI₄, Th(OH)₄, Th(O₂O₄)₂,Th(SO₄)₂, Sr(OH)₂, SrCO₃, SrO, SrCl₂, SrBr₂, SrI₂, SrC₂O₄, SrSO₄, Sm₂O₃,SmCl₃, SmBr₃, SmI₃, Sm(OH)₃, Sm₂(CO3)₃, Sm₂(C₂O₃)₃, Sm₂(SO₄)₃,LiCa₂Bi₃O₄Cl₆, Na₂WO₄, K/SrCoO₃, K/Na/SrCoO₃, Li/SrCoO₃, SrCoO₃,molybdenum oxides, molybdenum hydroxides, molybdenum chlorides,molybdenum bromides, molybdenum iodides, molybdenum oxalates, molybdenumsulfates, manganese oxides, manganese chlorides, manganese bromides,manganese iodides, manganese hydroxides, manganese oxalates, manganesesulfates, manganese tugstates, vanadium oxides, vanadium chlorides,vanadium bromides, vanadium iodides, vanadium hydroxides, vanadiumoxalates, vanadium sulfates, tungsten oxides, tungsten chlorides,tungsten bromides, tungsten iodides, tungsten hydroxides, tungstenoxalates, tungsten sulfates, neodymium oxides, neodymium chlorides,neodymium bromides, neodymium iodides, neodymium hydroxides, neodymiumoxalates, neodymium sulfates, europium oxides, europium chlorides,europium bromides, europium iodides, europium hydroxides, europiumoxalates, europium sulfates rhenium oxides, rhenium chlorides, rheniumbromides, rhenium iodides, rhenium hydroxides, rhenium oxalates, rheniumsulfates, chromium oxides, chromium chlorides, chromium bromides,chromium iodides, chromium hydroxides, chromium oxalates, chromiumsulfates, potassium molybdenum oxides and the like.

“Salt” means a compound comprising negative and positive ions. Salts aregenerally comprised of metallic cations and non-metallic counter ions.Under appropriate conditions, e.g., the solution also comprises atemplate, the metal ion (M^(n+)) and the anion (X^(m−)) bind to thetemplate to induce nucleation and growth of a nanowire of M_(m)X_(n) onthe template. “Anion precursor” thus is a compound that comprises ananion and a cationic counter ion, which allows the anion (X^(m−))dissociate from the cationic counter ion in a solution. Specificexamples of the metal salt and anion precursors are described in furtherdetail herein.

“Oxide” refers to a metal compound comprising oxygen. Examples of oxidesinclude, but are not limited to, metal oxides (M_(x)O_(y)), metaloxyhalide (M_(x)O_(y)X_(z)), metal oxynitrates (M_(x)O_(y)(NO₃)_(z)),metal phosphates (M_(x)(PO₄)_(y)), metal oxide carbonates(M_(x)O_(y)(CO₃)_(z)), metal carbonates and the like, wherein x, y and zare numbers from 1 to 100.

“Crystal domain” means a continuous region over which a substance iscrystalline.

“Single-crystalline nanowires” means a nanowire having a single crystaldomain.

“Template” is any synthetic and/or natural material that provides atleast one nucleation site where ions can nucleate and grow to formnanoparticles. In certain embodiments, the templates can be amulti-molecular biological structure comprising one or morebiomolecules. Typically, the biological template comprises multiplebinding sites that recognize certain ions and allow for the nucleationand growth of the same. Non-limiting examples of biological templatesinclude bacteriophages, amyloid fibers, viruses and capsids.

“Biomolecule” refers to any organic molecule of a biological origin.Biomolecule includes modified and/or degraded molecules of a biologicalorigin. Non-limiting examples of biomolecules include peptides, proteins(including cytokines, growth factors, etc.), nucleic acids,polynucleotides, amino acids, antibodies, enzymes, and single-strandedor double-stranded nucleic acid, including any modified and/or degradedforms thereof.

“Amyloid fibers” refers to proteinaceous filaments of about 1-25 nm indiameter.

A “bacteriophage” or “phage” is any one of a number of viruses thatinfect bacteria. Typically, bacteriophages consist of an outer proteincoat or “major coat protein” enclosing genetic material. A non-limitingexample of a bacteriophage is the M13 bacteriophage. Non-limitingexamples of bacteriophage coat proteins include the pIII, pV, pVIII,etc. protein as described in more detail below.

A “capsid” is the protein shell of a virus. A capsid comprises severaloligomeric structural subunits made of proteins.

“Nucleation” refers to the process of forming a solid from solubilizedparticles, for example forming a nanowire in situ by converting asoluble precursor (e.g. metal and hydroxide ions) into nanocrystals inthe presence of a template.

“Nucleation site” refers to a site on a template, for example abacteriophage, where nucleation of ions may occur. Nucleation sitesinclude, for example, amino acids having carboxylic acid (—COOH), amino(—NH₃ ⁺ or —NH₂), hydroxyl (—OH), and/or thiol (—SH) functional groups.

A “peptide” refers to two or more amino acids joined by peptide (amide)bonds. The amino-acid building blocks (subunits) include naturallyoccurring α-amino acids and/or unnatural amino acids, such as β-aminoacids and homoamino acids. An unnatural amino acid can be a chemicallymodified form of a natural amino acid. Peptides can be comprised of 2 ormore, 5 or more, 10 or more, 20 or more, or 40 or more amino acids.

“Peptide sequence” refers to the sequence of amino acids within apeptide or protein.

“Protein” refers to a natural or engineered macromolecule having aprimary structure characterized by peptide sequences. In addition to theprimary structure, proteins also exhibit secondary and tertiarystructures that determine their final geometric shapes.

“Polynucleotide” means a molecule comprised of two or more nucleotidesconnected via an internucleotide bond (e.g. a phosphate bond).Polynucleotides may be comprised of both ribose and/or deoxy ribosenucleotides. Examples of nucleotides include guanosine, adenosine,thiamine, and cytosine, as well as unnatural analogues thereof.

“Nucleic acid” means a macromolecule comprised of polynucleotides.Nucleic acids may be both single stranded and double stranded, and, likeproteins, can exhibit secondary and tertiary structures that determinetheir final geometric shapes.

“Nucleic acid sequence” of “nucleotide sequence” refers to the sequenceof nucleotides within a polynucleotide or nucleic acid.

“Anisotropic” means having an aspect ratio greater than one.

“Anisotropic biomolecule” means a biomolecule, as defined herein, havingan aspect ratio greater than 1. Non-limiting examples of anisotropicbiomolecules include bacteriophages, amyloid fibers, and capsids.

“Turnover number” is a measure of the number of reactant molecules acatalyst can convert to product molecules per unit time.

“Dopant” or “doping agent” is an impurity added to or incorporatedwithin a catalyst to optimize catalytic performance (e.g. increase ordecrease catalytic activity). As compared to the undoped catalyst, adoped catalyst may increase or decrease the selectivity, conversion,and/or yield of a reaction catalyzed by the catalyst.

“Atomic percent” (at %) or “atomic ratio” when used in the context ofnanowire dopants refers to the ratio of the total number of dopant atomsto the total number of non-oxygen atoms in the nanowire. For example,the atomic percent of dopant in a lithium doped Mg₆MnO₈ nanowire isdetermined by calculating the total number of lithium atoms and dividingby the sum of the total number of magnesium and manganese atoms andmultiplying by 100 (i.e., atomic percent of dopant=[Li atoms/(Mgatoms+Mn atoms)]×100)

“Group 1” elements include lithium (Li), sodium (Na), potassium (K),rubidium (Rb), cesium (Cs), and francium (Fr).

“Group 2” elements include beryllium (Be), magnesium (Mg), calcium (Ca),strontium (Sr), barium (Ba), and radium (Ra).

“Group 3” elements include scandium (Sc) and yttrium (Y).

“Group 4” elements include titanium (Ti), zirconium (Zr), halfnium (Hf),and rutherfordium (Rf).

“Group 5” elements include vanadium (V), niobium (Nb), tantalum (Ta),and dubnium (Db).

“Group 6” elements include chromium (Cr), molybdenum (Mo), tungsten (W),and seaborgium (Sg).

“Group 7” elements include manganese (Mn), technetium (Tc), rhenium(Re), and bohrium (Bh).

“Group 8” elements include iron (Fe), ruthenium (Ru), osmium (Os), andhassium (Hs).

“Group 9” elements include cobalt (Co), rhodium (Rh), iridium (Ir), andmeitnerium (Mt).

“Group 10” elements include nickel (Ni), palladium (Pd), platinum (Pt)and darmistadium (Ds).

“Group 11” elements include copper (Cu), silver (Ag), gold (Au), androentgenium (Rg).

“Group 12” elements include zinc (Zn), cadmium (Cd), mercury (Hg), andcopernicium (Cn).

“Lanthanides” include lanthanum (La), cerium (Ce), praseodymium (Pr),neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu),gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium(Er), thulium (Tm), yitterbium (Yb), and lutetium (Lu).

“Actinides” include actinium (Ac), thorium (Th), protactinium (Pa),uranium (U), neptunium (Np), plutonium (Pu), americium (Am), curium(Cm), berklelium (Bk), californium (Cf), einsteinium (Es), fermium (Fm),mendelevium (Md), nobelium (No), and lawrencium (Lr).

“Metal element” or “metal” is any element, except hydrogen, selectedfrom Groups 1 through XII, lanthanides, actinides, aluminum (Al),gallium (Ga), indium (In), tin (Sn), thallium (Tl), lead (Pb), andbismuth (Bi). Metal elements include metal elements in their elementalform as well as metal elements in an oxidized or reduced state, forexample, when a metal element is combined with other elements in theform of compounds comprising metal elements. For example, metal elementscan be in the form of hydrates, salts, oxides, as well as variouspolymorphs thereof, and the like.

“Semi-metal element” refers to an element selected from boron (B),silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium(Te), and polonium (Po).

“Non-metal element” refers to an element selected from carbon (C),nitrogen (N), oxygen (O), fluorine (F), phosphorus (P), sulfur (S),chlorine (Cl), selenium (Se), bromine (Br), iodine (I), and astatine(At).

“Conversion” means the mole fraction (i.e., percent) of a reactantconverted to a product or products.

“Selectivity” refers to the percent of converted reactant that went to aspecified product, e.g., C2 selectivity is the % of methane that formedethane and ethylene, C3 selectivity is the % of methane that formedpropane and propylene, CO selectivity is the percent of methane thatformed CO.

“Yield” is a measure of (e.g. percent) of product obtained relative tothe theoretical maximum product obtainable. Yield is calculated bydividing the amount of the obtained product in moles by the theoreticalyield in moles. Percent yield is calculated by multiplying this value by100.

“Bulk catalyst” or “bulk material” means a catalyst prepared bytraditional techniques, for example by milling or grinding largecatalyst particles to obtain smaller/higher surface area catalystparticles. Bulk materials are prepared with minimal control over thesize and/or morphology of the material.

“Alkane” means a straight chain or branched, noncyclic or cyclic,saturated aliphatic hydrocarbon. Alkanes include linear, branched andcyclic structures. Representative straight chain alkyls include methyl,ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, and the like; whilebranched alkyls include isopropyl, sec-butyl, isobutyl, tert-butyl,isopentyl, and the like. Representative cyclic alkyls includecyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and the like. “Alkene”means a straight chain or branched, noncyclic or cyclic, unsaturatedaliphatic hydrocarbon having at least one carbon-carbon double bond.Alkenes include linear, branched and cyclic structures. Representativestraight chain and branched alkenes include ethylenyl, propylenyl,1-butenyl, 2-butenyl, isobutylenyl, 1-pentenyl, 2-pentenyl,3-methyl-1-butenyl, 2-methyl-2-butenyl, 2,3-dimethyl-2-butenyl, and thelike. Cyclic alkenes include cyclohexene and cyclopentene and the like.

“Alkyne” means a straight chain or branched, noncyclic or cyclic,unsaturated aliphatic hydrocarbon having at least one carbon-carbontriple bond. Alkynes include linear, branched and cyclic structures.Representative straight chain and branched alkynes include acetylenyl,propynyl, 1-butynyl, 2-butynyl, 1-pentynyl, 2-pentynyl,3-methyl-1-butynyl, and the like. Representative cyclic alkynes includecycloheptyne and the like.

“Aromatic” means a carbocyclic moiety having a cyclic system ofconjugated p orbitals forming a delocalized conjugated π system and anumber of π electrons equal to 4n+2 with n=0, 1, 2, 3, etc.Representative examples of aromatics include benzene and naphthalene andtoluene.

“Carbon-containing compounds” are compounds which comprise carbon.Non-limiting examples of carbon-containing compounds includehydrocarbons, CO and CO₂.

Nanowires

1. Structure/Physical Characteristics

FIG. 3A is a TEM image of a polycrystalline nanowire 200 having twodistal ends 210 and 220. As shown, an actual length 230 essentiallytraces along the backbone of the nanowire 200, whereas an effectivelength 234 is the shortest distance between the two distal ends. Theratio of the effective length to the actual length is an indicator ofthe degrees of twists, bends and/or kinks in the general morphology ofthe nanowire. FIG. 3B is a schematic representation of the nanowire 200of FIG. 3A. Typically, the nanowire is not uniform in its thickness ordiameter. At any given location along the nanowire backbone, a diameter(240 a, 240 b, 240 c, 240 d) is the longest dimension of a cross sectionof the nanowire, i.e., is perpendicular to the axis of the nanowirebackbone).

Compared to nanowire 200 of FIG. 3A, nanowire 250 of FIG. 4A has adifferent morphology and does not exhibit as many twists, bends andkinks, which suggests a different underlying crystal structure anddifferent number of defects and/or stacking faults. As shown, fornanowire 250, the ratio of the effective length 270 and the actuallength 260 is greater than the ratio of the effective length 234 and theactual length 240 of nanowire 200 of FIG. 3A. FIG. 4B is a schematicrepresentation of the nanowire 250, which shows non-uniform diameters(280 a, 280 b, 280 c and 280 d).

As noted above, in some embodiments nanowires having a “bent” morphology(i.e. “bent nanowires”) are provided. A “bent’ morphology means that thebent nanowires comprise various twists, bends and/or kinks in theirgeneral morphology as illustrated generally in FIGS. 3A and 3B anddiscussed above. Bent nanowires have a ratio of effective length toactual length of less than one. Accordingly, in some embodiments thepresent disclosure provides nanowires having a ratio of effective lengthto actual length of less than one. In other embodiments, the nanowireshave a ratio of effective length to actual length of between 0.9 and0.1, between 0.8 and 0.2, between 0.7 and 0.3, or between 0.6 and 0.4.In other embodiments, the ratio of effective length to actual length isless than 0.9, less than 0.8, less than 0.7, less than 0.6, less than0.5, less than 0.4, less than 0.3, less than 0.2 or less than 0.1. Inother embodiments, the ratio of effective length to actual length isless than 1.0 and more than 0.9, less than 1.0 and more than 0.8, lessthan 1.0 and more than 0.7, less than 1.0 and more than 0.6, less than1.0 and more than 0.5, less than 1.0 and more than 0.4, less than 1.0and more than 0.3, less than 1.0 and more than 0.2, or less than 1.0 andmore than 0.1.

The ratio of effective length to actual length of a nanowire having abent morphology may vary depending on the angle of observation. Forexample, one-skilled in the art will recognize that the same nanowire,when observed from different perspectives, can have a differenteffective length as determined by TEM. In addition, not all nanowireshaving a bent morphology will have the same ratio of effective length toactual length. Accordingly, in a population (i.e. plurality) ofnanowires having a bent morphology, a range of ratios of effectivelength to actual length is expected. Although the ratio of effectivelength to actual length may vary from nanowire to nanowire, nanowireshaving a bent morphology will always have a ratio of effective length toactual length of less than one from any angle of observation.

In various embodiments, a substantially straight nanowire is provided. Asubstantially straight nanowire has a ratio of effective length toactual length equal to one. Accordingly, in some embodiments, thenanowires of the present disclosure have a ratio of effective length toactual length equal to one.

The actual lengths of the nanowires disclosed herein may vary. Forexample in some embodiments, the nanowires have an actual length ofbetween 100 nm and 100 μm. In other embodiments, the nanowires have anactual length of between 100 nm and 10 μm. In other embodiments, thenanowires have an actual length of between 200 nm and 10 μm. In otherembodiments, the nanowires have an actual length of between 500 nm and 5μm. In other embodiments, the actual length is greater than 5 μm. Inother embodiments, the nanowires have an actual length of between 800 nmand 1000 nm. In other further embodiments, the nanowires have an actuallength of 900 nm. As noted below, the actual length of the nanowires maybe determined by TEM, for example, in bright field mode at 5 keV.

The diameter of the nanowires may be different at different points alongthe nanowire backbone. However, the nanowires comprise a mode diameter(i.e. the most frequently occurring diameter). As used herein, thediameter of a nanowire refers to the mode diameter. In some embodiments,the nanowires have a diameter of between 1 nm and 500 nm, between 1 nmand 100 nm, between 7 nm and 100 nm, between 7 nm and 50 nm, between 7nm and 25 nm, or between 7 nm and 15 nm. On other embodiments, thediameter is greater than 500 nm. As noted below, the diameter of thenanowires may be determined by TEM, for example, in bright field mode at5 keV.

Various embodiments of the present disclosure provide nanowires havingdifferent aspect ratios. In some embodiments, the nanowires have anaspect ratio of greater than 10:1. In other embodiments, the nanowireshave an aspect ratio greater than 20:1. In other embodiments, thenanowires have an aspect ratio greater than 50:1. In other embodiments,the nanowires have an aspect ratio greater than 100:1.

In some embodiments, the nanowires comprise a solid core while in otherembodiments, the nanowires comprise a hollow core.

The morphology of a nanowire (including length, diameter, and otherparameters) can be determined by transmission electron microscopy (TEM).Transmission electron microscopy (TEM) is a technique whereby a beam ofelectrons is transmitted through an ultra thin specimen, interactingwith the specimen as it passes through. An image is formed from theinteraction of the electrons transmitted through the specimen. The imageis magnified and focused onto an imaging device, such as a fluorescentscreen, on a layer of photographic film or detected by a sensor such asa CCD camera. TEM techniques are well known to those of skill in theart.

A TEM image of nanowires may be taken, for example, in bright field modeat 5 keV (e.g., as shown in FIGS. 3A and 4A).

The nanowires of the present disclosure can be further characterized bypowder x-ray diffraction (XRD). XRD is a technique capable of revealinginformation about the crystallographic structure, chemical composition,and physical properties of materials, including nanowires. XRD is basedon observing the scattered intensity of an X-ray beam hitting a sampleas a function of incident and scattered angle, polarization, andwavelength or energy.

Crystal structure, composition, and phase, including the crystal domainsize of the nanowires, can be determined by XRD. In some embodiments,the nanowires comprise a single crystal domain (i.e. singlecrystalline). In other embodiments, the nanowires comprise multiplecrystal domains (i.e. polycrystalline). In some other embodiments, theaverage crystal domain of the nanowires is less than 100 nm, less than50 nm, less than 30 nm, less than 20 nm, less than 10 nm, less than 5nm, or less than 2 nm.

Typically, a catalytic material described herein comprises a pluralityof nanowires. In certain embodiments, the plurality of nanowires form amesh of randomly distributed and, to various degrees, interconnectednanowires. FIG. 5A is a TEM image of a nanowire mesh 300 comprising aplurality of nanowires 310 and a plurality of pores 320. FIG. 5B is aschematic representation of the nanowire mesh 300 of FIG. 5A.

The total surface area per gram of a nanowire or plurality of nanowiresmay have an effect on the catalytic performance. Pore size distributionmay affect the nanowires catalytic performance as well. Surface area andpore size distribution of the nanowires or plurality of nanowires can bedetermined by BET (Brunauer, Emmett, Teller) measurements. BETtechniques utilize nitrogen adsorption at various temperatures andpartial pressures to determine the surface area and pore sizes ofcatalysts. BET techniques for determining surface area and pore sizedistribution are well known in the art.

In some embodiments the nanowires have a surface area of between 0.0001and 3000 m²/g, between 0.0001 and 2000 m²/g, between 0.0001 and 1000m²/g, between 0.0001 and 500 m²/g, between 0.0001 and 100 m²/g, between0.0001 and 50 m²/g, between 0.0001 and 20 m²/g, between 0.0001 and 10m²/g or between 0.0001 and 5 m²/g.

In some embodiments the nanowires have a surface area of between 0.001and 3000 m²/g, between 0.001 and 2000 m²/g, between 0.001 and 1000 m²/g,between 0.001 and 500 m²/g, between 0.001 and 100 m²/g, between 0.001and 50 m²/g, between 0.001 and 20 m²/g, between 0.001 and 10 m²/g orbetween 0.001 and 5 m²/g.

In some other embodiments the nanowires have a surface area of between2000 and 3000 m²/g, between 1000 and 2000 m²/g, between 500 and 1000m²/g, between 100 and 500 m²/g, between 10 and 100 m²/g, between 5 and50 m²/g, between 2 and 20 m²/g or between 0.0001 and 10 m²/g.

In other embodiments, the nanowires have a surface area of greater than2000 m²/g, greater than 1000 m²/g, greater than 500 m²/g, greater than100 m²/g, greater than 50 m²/g, greater than 20 m²/g, greater than 10m²/g, greater than 5 m²/g, greater than 1 m²/g, greater than 0.0001m²/g.

2. Chemical Composition

As noted above, disclosed herein are nanowires useful as catalysts. Thecatalytic nanowires may have any number of compositions andmorphologies. In some embodiments, the nanowires are inorganic. In otherembodiments, the nanowires are polycrystalline. In some otherembodiments, the nanowires are inorganic and polycrystalline. In yetother embodiments, the nanowires are single-crystalline, or in otherembodiments the nanowires are inorganic and single-crystalline. In stillother embodiments, the nanowires are amorphous, for example thenanowires may be amorphous, polycrystalline or single crystalline. Instill other embodiments of any of the foregoing, the nanowires may havea ratio of effective length to actual length of less than one and anaspect ratio of greater than ten as measured by TEM in bright field modeat 5 keV. In still other embodiments of any of the forgoing, thenanowires may comprise one or more elements from any of Groups 1 through7, lanthanides, actinides or combinations thereof.

In some embodiments, the nanowires comprise one or more metal elementsfrom any of Groups 1-7, lanthanides, actinides or combinations thereof,for example, the nanowires may be mono-metallic, bi-metallic,tri-metallic, etc (i.e. contain one, two, three, etc. metal elements).In some embodiments, the metal elements are present in the nanowires inelemental form while in other embodiments the metal elements are presentin the nanowires in oxidized form. In other embodiments the metalelements are present in the nanowires in the form of a compoundcomprising a metal element. The metal element or compound comprising themetal element may be in the form of oxides, hydroxides, oxyhydroxides,salts, hydrates, oxide carbonates and the like. The metal element orcompound comprising the metal element may also be in the form of any ofa number of different polymorphs or crystal structures.

In certain examples, metal oxides may be hygroscopic and may changeforms once exposed to air. Accordingly, although the nanowires are oftenreferred to as metal oxides, in certain embodiments the nanowires alsocomprise hydrated oxides, oxyhydroxides, hydroxides or combinationsthereof.

In other embodiments, the nanowires comprise one or more metal elementsfrom Group I. In other embodiments, the nanowires comprise one or moremetal elements from Group 2. In other embodiments, the nanowirescomprise one or more metal elements from Group 3. In other embodiments,the nanowires comprise one or more metal elements from Group 4. In otherembodiments, the nanowires comprise one or more metal elements fromGroup 5. In other embodiments, the nanowires comprise one or more metalelements from Group 6. In other embodiments, the nanowires comprise oneor more metal elements from Group 7. In other embodiments, the nanowirescomprise one or more metal elements from the lanthanides. In otherembodiments, the nanowires comprise one or more metal elements from theactinides.

In one embodiment, the nanowires comprise one or more metal elementsfrom any of Groups 1-7, lanthanides, actinides or combinations thereofin the form of an oxide. In another embodiment, the nanowires compriseone or more metal elements from Group 1 in the form of an oxide. Inanother embodiment, the nanowires comprise one or more metal elementsfrom Group 2 in the form of an oxide. In another embodiment, thenanowires comprise one or more metal elements from Group 3 in the formof an oxide. In another embodiment, the nanowires comprise one or moremetal elements from Group 4 in the form of an oxide. In anotherembodiment, the nanowires comprise one or more metal elements from Group5 in the form of an oxide. In another embodiment, the nanowires compriseone or more metal elements from Group 6 in the form of an oxide. Inanother embodiment, the nanowires comprise one or more metal elementsfrom Group 7 in the form of an oxide. In another embodiment, thenanowires comprise one or more metal elements from the lanthanides inthe form of an oxide. In another embodiment, the nanowires comprise oneor more metal elements from the actinides in the form of an oxide.

In other embodiments, the nanowires comprise oxides, hydroxides,sulfates, carbonates, oxide carbonates, oxalates, phosphates (includinghydrogenphosphates and dihydrogenphosphates), oxyhalides,hydroxihalides, oxyhydroxides, oxysulfates or combinations thereof ofone or more metal elements from any of Groups I-7, lanthanides,actinides or combinations thereof. In some other embodiments, thenanowires comprise oxides, hydroxides, sulfates, carbonates, oxidecarbonates, oxalates or combinations thereof of one or more metalelements from any of Groups I-7, lanthanides, actinides or combinationsthereof. In other embodiments, the nanowires comprise oxides, and inother embodiments, the nanowires comprise hydroxides. In otherembodiments, the nanowires comprise oxide carbonates. In otherembodiments, the nanowires comprise Li₂CO₃, LiOH, Li₂O, Li₂C₂O₄, Li₂SO₄,Na₂CO₃, NaOH, Na₂O, Na₂C₂O₄, Na₂SO₄, K₂CO₃, KOH, K₂O, K₂C₂O₄, K₂SO₄,CsCO₃, CsOH, Cs₂O, CsC₂O₄, CsSO₄, Be(OH)₂, BeCO₃, BeO, BeC₂O₄. BeSO₄,Mg(OH)₂, MgCO₃, MgO, MgC₂O₄. MgSO₄, Ca(OH)₂, CaO, Ca(OH)₂, CaC₂O₄,CaSO₄, Y₂O₃, Y₂(CO3)₃, Y(OH)₃, Y₂(C₂O4)₃, Y₂(SO4)₃, Zr(OH)₄, ZrO(OH)₂,ZrO2, Zr(C₂O₄)₂, Zr(SO₄)₂, Ti(OH)₄, TiO(OH)₂, TiO2, Ti(C₂O₄)₂, Ti(SO₄)₂,BaO, Ba(OH)₂, BaCO₃, BaC₂O₄, BaSO₄, La(OH)₃, La₂O₃, La₂(C₂O₄)₃,La₂(SO₄)₃, Ce(OH)₄, CeO₂, Ce₂O₃, Ce(C₂O₄)₂, Ce(SO₄)₂, ThO₂, Th(OH)₄,Th(C₂O₄)₂, Th(SO₄)₂, Sr(OH)₂, SrCO₃, SrO, SrC₂O₄, SrSO₄, Sm₂O₃, Sm(OH)₃,Sm₂(CO3)₃, Sm₂(C₂O₃)₃, Sm₂(SO₄)₃, LiCa₂Bi₃O₄Cl₆, NaMnO₄, Na₂WO₄,NaMn/WO₄, CoWO₄, CuWO₄, K/SrCoO₃, K/Na/SrCoO₃, Na/SrCoO₃, Li/SrCoO₃,SrCoO₃, Mg₆MnO₈, LiMn₂O₄, Li/Mg₆MnO₈, Na₁₀Mn/W₅O₁₇, Mg₃Mn₃B₂O₁₀,Mg₃(BO3)₂, molybdenum oxides, molybdenum hydroxides, molybdenumoxalates, molybdenum sulfates, Mn₂O₃, Mn₃O₄, manganese oxides, manganesehydroxides, manganese oxalates, manganese sulfates, manganesetungstates, vanadium oxides, vanadium hydroxides, vanadium oxalates,vanadium sulfates, tungsten oxides, tungsten hydroxides, tungstenoxalates, tungsten sulfates, neodymium oxides, neodymium hydroxides,neodymium oxalates, neodymium sulfates, europium oxides, europiumhydroxides, europium oxalates, europium sulfates, praseodymium oxides,praseodymium hydroxides, praseodymium oxalates, praseodymium sulfates,rhenium oxides, rhenium hydroxides, rhenium oxalates, rhenium sulfates,chromium oxides, chromium hydroxides, chromium oxalates, chromiumsulfates, potassium molybdenum oxides/silicon oxide or combinationsthereof.

In other embodiments, the nanowires comprise Li₂O, Na₂O, K₂O, Cs₂O, BeOMgO, CaO, ZrO(OH)₂, ZrO2, TiO₂, TiO(OH)₂, BaO, Y₂O₃, La₂O₃, CeO₂, Ce₂O₃,ThO₂, SrO, Sm₂O₃, Nd₂O₃, Eu₂O₃, Pr₂O₃, LiCa₂Bi₃O₄Cl₆, NaMnO₄, Na₂WO₄,Na/Mn/WO₄, Na/MnWO₄, Mn/WO₄, K/SrCoO₃, K/Na/SrCoO₃, K/SrCoO₃, Na/SrCoO₃,Li/SrCoO₃, SrCoO₃, Mg₆MnO₈, Na/B/Mg₆MnO₈, Li/B/Mg₆MnO₈, Zr₂Mo₂O₈,molybdenum oxides, Mn₂O₃, Mn₃O₄, manganese oxides, vanadium oxides,tungsten oxides, neodymium oxides, rhenium oxides, chromium oxides, orcombinations thereof.

In still other aspects, the nanowires comprise lanthanide containingperovskites. A perovskite is any material with the same type of crystalstructure as calcium titanium oxide (CaTiO₃). Examples of perovskiteswithin the context of the present disclosure include, but are notlimited to, LaCoO₃ and La/SrCoO₃.

In other embodiments, the nanowires comprise TiO₂, Sm₂O₃, V₂O₅, MoO₃,BeO, MnO₂, MgO, La₂O₃, Nd₂O₃, Eu₂O₃, ZrO₂, SrO, Na₂WO₄, Mn/WO4, BaCO₃,Mn₂O₃, Mn₃O₄, Mg₆MnO₈, Na/B/Mg₆MnO₈, Li/B/Mg₆MnO₈, NaMnO₄, CaO orcombinations thereof. In further embodiments, the nanowires compriseMgO, La₂O₃, Nd2O3, Na₂WO₄, Mn/WO4, Mn₂O₃, Mn₃O₄, Mg₆MnO₈, Na/B/Mg₆MnO₈,Li/B/Mg₆MnO₈ or combinations thereof.

In some embodiments, the nanowires comprises Mg, Ca, La, W, Mn, Mo, Nd,Sm, Eu, Pr, Zr or combinations thereof, and in other embodiments thenanowire comprises MgO, CaO, La₂O₃, Na₂WO₄, Mn₂O₃, Mn₃O₄, Nd₂O₃, Sm₂O₃,Eu₂O₃, Pr₂O₃, Mg₆MnO₈, NaMnO₄, Na/Mn/W/O, Na/MnWO₄, MnWO₄ orcombinations thereof.

In more specific embodiments, the nanowires comprise MgO. In otherspecific embodiments, the nanowires comprise La₂O₃. In other specificembodiments, the nanowires comprise Na₂WO₄ and may optionally furthercomprise Mn/WO₄. In other specific embodiments, the nanowires compriseMn₂O₃. In other specific embodiments, the nanowires comprise Mn₃O₄. Inother specific embodiments, the nanowires comprise Mg₆MnO₈. In otherspecific embodiments, the nanowires comprise NaMnO₄. In other specificembodiments, the nanowires comprise Nd₂O₃. In other specificembodiments, the nanowires comprise Eu₂O₃. In other specificembodiments, the nanowires comprise Pr₂O₃.

In certain embodiments, the nanowires comprise an oxide of a group 2element. For example, in some embodiments, the nanowires comprise anoxide of magnesium. In other embodiments, the nanowires comprise anoxide of calcium. In other embodiments, the nanowires comprise an oxideof strontium. In other embodiments, the nanowires comprise an oxide ofbarium.

In certain other embodiments, the nanowires comprise an oxide of a group3 element. For example, in some embodiments, the nanowires comprise anoxide of yttrium. In other embodiments, the nanowires comprise an oxideof scandium.

In yet other certain embodiments, the nanowires comprise an oxide of anearly lanthanide element. For example, in some embodiments, thenanowires comprise an oxide of lanthanum. In other embodiments, thenanowires comprise an oxide of cerium. In other embodiments, thenanowires comprise an oxide of praseodymium. In other embodiments, thenanowires comprise an oxide of neodymium. In other embodiments, thenanowires comprise an oxide of promethium. In other embodiments, thenanowires comprise an oxide of samarium. In other embodiments, thenanowires comprise an oxide of europium. In other embodiments, thenanowires comprise an oxide of gandolinium.

In certain other embodiments, the nanowires comprise a lanthanide in theform of an oxide carbonate. For example, the nanowires may compriseLn₂O₂(CO₃), where Ln represents a lanthanide. Examples in this regardinclude: La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Luoxide carbonates. In other embodiments, the nanowires comprise an oxidecarbonate of one or more elements from any of Groups 1 through 7,lanthanides, actinides or combinations thereof. Accordingly in oneembodiment the nanowires comprise Li, Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr,Ba, Ra, Sc, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Tc or Re oxidecarbonate. In other embodiments, the nanowires comprise Ac, Th or Paoxide carbonate. An oxide carbonate may be represented by the followingformula: M_(x)O_(y)(CO₃)_(z), wherein M is a metal element from any ofGroups 1 through 7, lanthanides or actinides and x, y and z are integerssuch that the overall charge of the metal oxide carbonate is neutral.

In other embodiments, the nanowires comprise TiO₂, Sm₂O₃, V₂O₅, MoO₃,BeO, MnO₂, MgO, La₂O₃, ZrO₂, SrO, Na₂WO₄, BaCO₃, Mn₂O₃, Mn₃O₄, Mg₆MnO₈,Na/B/Mg₆MnO₈, Li/B/Mg₆MnO₈, Zr₂Mo₂O₈, NaMnO₄, CaO or combinationsthereof and further comprise one or more dopants comprised of metalelements, semi-metal elements, non-metal elements or combinationsthereof. In some further embodiments, the nanowires comprise MgO, La₂O₃,Na₂WO₄, Mn₂O₃, Mn₃O₄, Mg₆MnO₈, Zr₂Mo₂O₈, NaMnO₄ or combinations thereof,and the nanowires further comprise Li, Sr, Zr, Ba, Mn or Mn/WO₄.

In some embodiments, the nanowires or a catalytic material comprising aplurality of the nanowires comprise a combination of one or more ofmetal elements from any of Groups I-7, lanthanides or actinides and oneor more of metal elements, semi-metal elements or non-metal elements.For example in one embodiment, the nanowires comprise the combinationsof Li/Mg/O, Ba/Mg/O, Zr/La/O, Ba/La/O, Sr/La/O, Zr/V/P/O, Mo/V/Sb/O,V₂O₅/Al₂O₃, Mo/V/O, V/Ce/O, V/Ti/P/O, V₂O₅/TiO₂, V/P/O/TiO₂,V/P/O/Al₂O₃, V/Mg/O, V₂O₅/ZrO₂, Mo/V/Te/O, V/Mo/O/Al₂O₃, Ni/V/Sb/O,Co/V/Sb/O, Sn/V/Sb/O, Bi/V/Sb/O, Mo/V/Te/Nb/O, Mo/V/Nb/O, V₂O₅/MgO/SiO₂,V/Co, MoO₃/Al₂O₃, Ni/Nb/O, NiO/Al₂O₃, Ga/Cr/Zr/P/O, MoO₃/Cl/SiO₂/TiO₂,Co/Cr/Sn/W/O, Cr/Mo/O, MoO₃/Cl/SiO₂/TiO₂, Co/Ca, NiO/MgO, MoO₃/Al₂O₃,Nb/P/Mo/O, Mo/V/Te/Sb//Nb/O, La/Na/Al/O, Ni/Ta/Nb/O, Mo/Mn/V/W/O,Li/Dy/Mg/O, Sr/La/Nd/O, Co/Cr/Sn/W/O, MoO₃/SiO₂/TiO₂, Sm/Na/P/O,Sm/Sr/O, Sr/La/Nd/O, Co/P/O/TiO₂, La/Sr/Fe/Cl/O, La/Sr/Cu/Cl/O,Y/Ba/Cu/O, Na/Ca/O, V₂O₅/ZrO₂, V/Mg/O, Mn/V/Cr/W/O/Al₂O₃, V₂O₅/K/SiO₂,V₂O₅/Ca/TiO₂, V₂O₅/K/TiO₂, V/Mg/Al/O, V/Zr/O, V/Nb/O, V₂O₅/Ga₂O₃,V/Mg/Al/O, V/Nb/O, V/Sb/O, V/Mn/O, V/Nb/O/Sb₂O₄, V/Sb/O/TiO₂, V₂O₅/Ca,V₂O₅/K/Al₂O₃, V₂O₅/TiO₂, V₂O₅/MgO/TiO₂, V₂O₅/ZrO₂, V/Al/F/O,V/Nb/O/TiO₂, Ni/V/O, V₂O₅/SmVO₄, V/W/O, V₂O₅/Zn/Al₂O₃, V₂O₅/CeO₂,V/Sm/O, V₂O₅/TiO₂/SiO₂, Mo/Li/O/Al₂O₃, Mg/Dy/Li/Cl/O, Mg/Dy/Li/Cl/O,Ce/Ni/O, Ni/Mo/O/V, Ni/Mo/O/V/N, Ni/Mo/O Sb/O/N, MoO₃/Cl/SiO₂/TiO₂,Co/Mo/O, Ni/Ti/O, Ni/Zr/O, Cr/O, MoO₃/Al₂O₃, Mn/P/O, MoO₃/K/ZrO₂,Na/W/O, Mn/Na/W/O, Mn/Na//W/O/SiO₂, Na/W/O/SiO₂, Mn/Mo/O, Nb₂O₅/TiO₂,Co/W/O, Ni/Mo/O, Ga/Mo/O, Mg/Mo/V/O, Cr₂O₃/Al₂O₃, Cr/Mo/Cs/O/Al₂O₃,Co/Sr/O/Ca, Ag/Mo/P/O, MoO₃/SmVO₄, Mo/Mg/Al/O, MoO₃/K/SiO₂/TiO₂,Cr/Mo/O/Al₂O₃, MoO₃/Al₂O₃, Ni/Co/Mo/O, Y/Zr/O, Y/Hf, Zr/Mo/Mn/O,Mg/Mn/O, Li/Mn/O, Mg/Mn/B/O, Mg/B/O, Na/B/Mg/Mn/O, Li/B/Mg/Mn/O,Mn/Na/P/O, Na/Mn/Mg/O, Zr/Mo/O, Mn/W/O or Mg/Mn/O.

In a specific embodiment, the nanowires comprise the combinations ofLi/Mg/O, Ba/Mg/O, Zr/La/O, Ba/La/O, Sr/La/O, Sr/Nd/O, La/O, Nd/O, Eu/O,Mg/La/O, Mg/Nd/O, Na/La/O, Na/Nd/O, Sm/O, Mn/Na/W/O, Mg/Mn/O,Na/B/Mg/Mn/O, Li/B/Mg/Mn/O, Zr/Mo/O or Na/Mn/Mg/O. For example, in someembodiments the nanowires comprise the combinations of Li/MgO, Ba/MgO,Sr/La₂O₃, Ba/La₂O₃, Mn/Na₂WO₄, Mn/Na₂WO₄/SiO₂, Mn₂O₃/Na₂WO₄,Mn₃O₄/Na₂WO₄, Li/B/Mg₆MnO₈, Na/B/Mg₆MnO₈ or NaMnO₄/MgO. In certainembodiments, the nanowire comprises Li/MgO, Ba/MgO, Sr/La₂O₃,Mg/Na/La₂O₃, Sr/Nd₂O₃, or Mn/Na₂WO₄.

In some other specific embodiments, the nanowires comprise thecombination of Li/MgO. In other specific embodiments, the nanowirescomprise the combination of Ba/MgO. In other specific embodiments, thenanowires comprise the combination of Sr/La₂O₃. In other specificembodiments, the nanowires comprise the combination of Ba/La₂O₃. Inother specific embodiments, the nanowires comprise the combination ofMn/Na₂WO₄. In other specific embodiments, the nanowires comprise thecombination of Mn/Na₂WO₄/SiO₂. In other specific embodiments, thenanowires comprise the combination of Mn₂O₃/Na₂WO₄. In other specificembodiments, the nanowires comprise the combination of Mn₃O₄/Na₂WO₄. Inother specific embodiments, the nanowires comprise the combination ofMn/WO₄/Na₂WO₄. In other specific embodiments, the nanowires comprise thecombination of Li/B/Mg₆MnO₈. In other specific embodiments, thenanowires comprise the combination of Na/B/Mg₆MnO₈. In other specificembodiments, the nanowires comprise the combination of NaMnO₄/MgO.

Polyoxyometalates (POM) are a class of metal oxides that range instructure from the molecular to the micrometer scale. The uniquephysical and chemical properties of POM clusters, and the ability totune these properties by synthetic means have attracted significantinterest from the scientific community to create “designer” materials.For example, heteropolyanions such as the well-known Keggin [XM₁₂O₄₀]⁻and Wells-Dawson [X₂M1₈O₆₂]⁻ anions (where M=W or Mo; and X=atetrahedral template such as but not limited to Si, Ge, P) andisopolyanions with metal oxide frameworks with general formulas[MO_(x)]_(n) where M=Mo, W, V, and Nb and x=4−7 are ideal candidates forOCM/ODH catalysts. Accordingly, in one embodiment the nanowires comprise[XM₁₂O₄₀]⁻ or [X₂M1₈O₆₂]⁻ anions (where M=W or Mo; and X=a tetrahedraltemplate such as but not limited to Si, Ge, P) and isopolyanions withmetal oxide frameworks with general formulas [MO_(x)]_(n) where M=Mo, W,V, and Nb and x=4−7. In some embodiments, X is P or Si.

These POM clusters have “lacunary” sites that can accommodate divalentand trivalent first row transition metals, the metal oxide clustersacting as ligands. These lacunary sites are essentially “doping” sites,allowing the dopant to be dispersed at the molecular level instead of inthe bulk which can create pockets of unevenly dispersed doped material.Because the POM clusters can be manipulated by standard synthetictechniques, POMs are highly modular and a wide library of materials canbe prepared with different compositions, cluster size, and dopantoxidation state. These parameters can be tuned to yield desired OCM/ODHcatalytic properties. Accordingly, one embodiment of the presentdisclosure is a nanowire comprising one or more POM clusters. Suchnanowires find utility as catalysts, for example, in the OCM and ODHreactions.

Silica doped sodium manganese tungstate (NaMn/WO₄/SiO₂) is a promisingOCM catalyst. The NaMn/WO₄/SiO₂ system is attractive due to its high C2selectivity and yield. Unfortunately, good catalytic activity is onlyachievable at temperatures greater than 800° C. and although the exactactive portion of the catalyst is still subject to debate, it is thoughtthat sodium plays an important role in the catalytic cycle. In addition,the NaMn/WO₄/SiO₂ catalyst surface area is relatively low <2 m²/g.Manganese tungstate (Mn/WO₄) nanorods (i.e., straight nanowires) can beused to model a NaMn/WO₄/SiO₂ based nanowire OCM catalyst. The Mn/WO₄nanorods are prepared hydro-thermally and the size can be tuned based onreaction conditions with dimensions of 25-75 nm in diameter to 200-800nm in length. The as-prepared nano-rods have higher surface areas thanthe NaMn/WO₄/SiO₂ catalyst systems. In addition, the amount of sodium,or other elements, can precisely doped into the Mn/WO₄ nanorod materialto target optimal catalytic activity. Nanorod tungstate based materialscan be expanded to but, not limited to, CoWO₄ or CuWO₄ materials whichmay serve as base materials for OCM/ODH catalysis. In addition tostraight nanowires, the above discussion applies to the disclosednanowires having a bent morphology as well. The nanowires of thedisclosure may be analyzed by inductively coupled plasma massspectrometry (ICP-MS) to determine the element content of the nanowires.ICP-MS is a type of mass spectrometry that is highly sensitive andcapable of the determination of a range of metals and several non-metalsat concentrations below one part in 10¹². ICP is based on couplingtogether an inductively coupled plasma as a method of producing ions(ionization) with a mass spectrometer as a method of separating anddetecting the ions. ICP-MS methods are well known in the art.

In some embodiments, the nanowire comprises a combination of two or moremetal compounds, for example metal oxides. For example, in someembodiments, the nanowire comprises Mn₂O₃/Na₂WO₄, Mn₃O₄/Na₂WO₄MnWO₄/Na₂WO₄/Mn₂O₃, MnWO₄/Na₂WO₄/Mn₃O₄ or NaMnO₄/MgO.

3. Catalytic Materials

As noted above, the present disclosure provides a catalytic materialcomprising a plurality of nanowires. In certain embodiments, thecatalytic material comprises a support or carrier. The support ispreferably porous and has a high surface area. In some embodiments thesupport is active (i.e. has catalytic activity). In other embodiments,the support is inactive (i.e. non-catalytic). In some embodiments, thesupport comprises an inorganic oxide, Al₂O₃, SiO₂, TiO₂, MgO, ZrO₂, ZnO,LiAlO₂, MgAl₂O₄, MnO, MnO₂, Mn₃O₄, La₂O₃, AlPO4, SiO₂/Al₂O₃, activatedcarbon, silica gel, zeolites, activated clays, activated Al₂O₃,diatomaceous earth, magnesia, aluminosilicates, calcium aluminate,support nanowires or combinations thereof. In some embodiments thesupport comprises silicon, for example SiO₂. In other embodiments thesupport comprises magnesium, for example MgO. In other embodiments thesupport comprises zirconium, for example ZrO₂. In yet other embodiments,the support comprises lanthanum, for example La₂O₃. In yet otherembodiments, the support comprises hafnium, for example HfO₂. In yetother embodiments, the support comprises aluminum, for example Al₂O₃. Inyet other embodiments, the support comprises gallium, for example Ga₂O₃.

In still other embodiments, the support material comprises an inorganicoxide, Al₂O₃, SiO₂, TiO₂, MgO, ZrO₂, HfO2, CaO, ZnO, LiAlO₂, MgAl₂O₄,MnO, MnO₂, Mn₂O₄, Mn₃O₄, La₂O₃, activated carbon, silica gel, zeolites,activated clays, activated Al₂O₃, diatomaceous earth, magnesia,aluminosilicates, calcium aluminate, support nanowires or combinationsthereof. For example, the support material may comprise SiO₂, ZrO₂, CaO,La₂O₃ or MgO.

In yet other embodiments, a nanowire may serve as a support for anothernanowire. For example, a nanowire may be comprised of non-catalyticmetal elements and adhered to or incorporated within the supportnanowire is a catalytic nanowire. For example, in some embodiments, thesupport nanowires are comprised of SiO₂, MgO, TiO₂, ZrO₂, Al₂O₃, or ZnO.Preparation of nanowire supported nanowire catalysts (i.e., core/shellnanowires) is discussed in more detail below. The optimum amount ofnanowire present on the support depends, inter alia, on the catalyticactivity of the nanowire. In some embodiments, the amount of nanowirepresent on the support ranges from 1 to 100 parts by weight nanowiresper 100 parts by weight of support or from 10 to 50 parts by weightnanowires per 100 parts by weight of support. In other embodiments, theamount of nanowire present on the support ranges from 100-200 parts ofnanowires per 100 parts by weight of support, or 200-500 parts ofnanowires per 100 parts by weight of support, or 500-1000 parts ofnanowires per 100 parts by weight of support.

Typically, heterogeneous catalysts are used either in their pure form orblended with inert materials, such as silica, alumina, etc. The blendingwith inert materials is used in order to reduce and/or control largetemperature non-uniformities within the reactor bed often observed inthe case of strongly exothermic (or endothermic) reactions. In the caseof complex multistep reactions, such as the reaction to convert methaneinto ethylene (OCM), typical blending materials can selectively slowdown or quench one or more of the reactions of the system and promoteunwanted side reactions. For example, in the case of the oxidativecoupling of methane, silica and alumina can quench the methyl radicalsand thus prevent the formation of ethane. In certain aspects, thepresent disclosure provides a catalytic material which solves theseproblems typically associated with catalyst support material.Accordingly, in certain embodiments the catalytic activity of thecatalytic material can be tuned by blending two or more catalysts and/orcatalyst support materials. The blended catalytic material may comprisea catalytic nanowire as described herein and a bulk catalyst materialand/or inert support material.

The blended catalytic materials comprise metal oxides, hydroxides,oxy-hydroxides, carbonates, oxalates of the groups 1-16, lanthanides,actinides or combinations thereof. For example, the blended catalyticmaterials may comprise a plurality of inorganic catalyticpolycrystalline nanowires, as disclosed herein, and any one or more ofstraight nanowires, nanoparticles, bulk materials and inert supportmaterials. Bulk materials are defined as any material in which noattempt to control the size and/or morphology was performed during itssynthesis. The catalytic materials may be undoped or may be doped withany of the dopants described herein.

In one embodiment, the catalyst blend comprises at least one type 1component and at least one type 2 component. Type 1 components comprisecatalysts having a high OCM activity at moderately low temperatures andtype 2 components comprise catalysts having limited or no OCM activityat these moderately low temperatures, but are OCM active at highertemperatures. For example, in some embodiments the type 1 component is acatalyst (e.g., nanowire) having high OCM activity at moderately lowtemperatures. For example, the type 1 component may comprise a C2 yieldof greater than 5% or greater than 10% at temperatures less than 800°C., less than 700° C. or less than 600° C. The type 2 component maycomprise a C2 yield less than 0.1%, less than 1% or less than 5% attemperatures less than 800° C., less than 700° C. or less than 600° C.The type 2 component may comprise a C2 yield of greater than 0.1%,greater than 1%, greater than 5% or greater than 10% at temperaturesgreater than 800° C., greater than 700° C. or greater than 600° C.Typical type 1 components include nanowires, for example polycrystallinenanowires as described herein, while typical type 2 components includebulk OCM catalysts and nanowire catalysts which only have good OCMactivity at higher temperatures, for example greater than 800° C.Examples of type 2 components may include catalysts comprising MgO. Thecatalyst blend may further comprise inert support materials as describedabove (e.g., silica, alumina, etc.).

In certain embodiments, the type 2 component acts as diluent in the sameway an inert material does and thus helps reduce and/or control hotspots in the catalyst bed caused by the exothermic nature of the OCMreaction. However, because the type 2 component is an OCM catalyst,albeit not a particularly active one, it may prevent the occurrence ofundesired side reactions, e.g. methyl radical quenching. Additionally,controlling the hotspots has the beneficial effect of extending thelifetime of the catalyst.

For example, it has been found that diluting active lanthanide oxide OCMcatalysts (e.g., nanowires) with as much as a 10:1 ratio of MgO, whichby itself is not an active OCM catalyst at the temperature which thelanthanide oxide operates, is a good way to minimize “hot spots” in thereactor catalyst bed, while maintaining the selectivity and yieldperformance of the catalyst. On the other hand, doing the same dilutionwith quartz SiO₂ is not effective because it appears to quench themethyl radicals which serves to lower the selectivity to C2s.

In yet another embodiment, the type 2 components are good oxidativedehydrogenation (ODH) catalysts at the same temperature that the type 1components are good OCM catalysts. In this embodiment, theethylene/ethane ratio of the resulting gas mixture can be tuned in favorof higher ethylene. In another embodiment, the type 2 components are notonly good ODH catalysts at the same temperature the type 1 componentsare good OCM catalysts, but also have limited to moderate OCM activityat these temperatures.

In related embodiments, the catalytic performance of the catalyticmaterial is tuned by selecting specific type 1 and type 2 components ofa catalyst blend. In another embodiment, the catalytic performance istuned by adjusting the ratio of the type 1 and type 2 components in thecatalytic material. For example, the type 1 catalyst may be a catalystfor a specific step in the catalytic reaction, while the type 2 catalystmay be specific for a different step in the catalytic reaction. Forexample, the type 1 catalyst may be optimized for formation of methylradicals and the type 2 catalyst may be optimized for formation ofethane or ethylene.

In other embodiments, the catalyst material comprises at least twodifferent components (component 1, component 2, component 3, etc.). Thedifferent components may comprise different morphologies, e.g.nanowires, nanoparticles, bulk, etc. The different components in thecatalyst material can be, but not necessarily, of the same chemicalcomposition and the only difference is in the morphology and/or the sizeof the particles. This difference in morphology and particle size mayresult in a difference in reactivity at a specific temperature.Additionally, the difference in morphology and particle size of thecatalytic material components is advantageous for creating a veryintimate blending, e.g. very dense packing of the catalysts particles,which can have a beneficial effect on catalyst performance. Also, thedifference in morphology and particle size of the blend components wouldallow for control and tuning of the macro-pore distribution in thereactor bed and thus its catalytic efficiency. An additional level ofmicro-pore tuning can be attained by blending catalysts with differentchemical composition and different morphology and/or particle size. Theproximity effect would be advantageous for the reaction selectivity.

Accordingly, in one embodiment the present disclosure provides the useof a catalytic material comprising a first catalytic nanowire and a bulkcatalyst and/or a second catalytic nanowire in a catalytic reaction, forexample the catalytic reaction may be OCM or ODH. In other embodiments,the first catalytic nanowire and the bulk catalyst and/or secondcatalytic nanowire are each catalytic with respect to the same reaction,and in other examples the first catalytic nanowire and the bulk catalystand/or second catalytic nanowire have the same chemical composition.

In some specific embodiments of the foregoing, the catalytic materialcomprises a first catalytic nanowire and a second catalytic nanowire.Each nanowire can have completely different chemical compositions orthey may have the same base composition and differ only by the dopingelements. In other embodiments, each nanowire can have the same or adifferent morphology. For example, each nanowire can differ by thenanowire size (length and/or aspect ratio), by ratio of actual/effectivelength, by chemical composition or any combination thereof. Furthermore,the first and second nanowires may each be catalytic with respect to thesame reaction but may have different activity. Alternatively, eachnanowire may catalyze different reactions.

In a related embodiment, the catalytic material comprises a firstcatalytic nanowire and a bulk catalyst. The first nanowire and the bulkcatalyst can have completely different chemical compositions or they mayhave the same base composition and differ only by the doping elements.Furthermore, the first nanowire and the bulk catalyst may each becatalytic with respect to the same reaction but may have differentactivity. Alternatively, the first nanowire and the bulk catalyst maycatalyze different reactions.

In yet other embodiments of the foregoing, the catalytic nanowire has acatalytic activity in the catalytic reaction which is greater than acatalytic activity of the bulk catalyst in the catalytic reaction at thesame temperature. In still other embodiments, the catalytic activity ofthe bulk catalyst in the catalytic reaction increases with increasingtemperature.

For ease of illustration, the above description of catalytic materialsoften refers to OCM; however, such catalytic materials find utility inother catalytic reactions including but not limited to: oxidativedehydrogenation (ODH) of alkanes to their corresponding alkenes,selective oxidation of alkanes and alkenes and alkynes, oxidation of co,dry reforming of methane, selective oxidation of aromatics,Fischer-Tropsch, combustion of hydrocarbons, etc.

4. Preparation of Catalytic Materials

The catalytic materials can be prepared according to any number ofmethods known in the art. For example, the catalytic materials can beprepared after preparation of the individual components by mixing theindividual components in their dry form, e.g. blend of powders, andoptionally, ball milling can be used to reduce particle size and/orincrease mixing. Each component can be added together or one after theother to form layered particles. Alternatively, the individualcomponents can be mixed prior to calcination, after calcination or bymixing already calcined components with uncalcined components. Thecatalytic materials may also be prepared by mixing the individualcomponents in their dry form and optionally pressing them together intoa “pill” followed by calcination to above 400° C.

In other examples, the catalytic materials are prepared by mixing theindividual components with one or more solvents into a suspension orslurry, and optional mixing and/or ball milling can be used to maximizeuniformity and reduce particle size. Examples of slurry solvents usefulin this context include, but are not limited to: water, alcohols,ethers, carboxylic acids, ketones, esters, amides, aldehydes, amines,alkanes, alkenes, alkynes, aromatics, etc. In other embodiments, theindividual components are deposited on a supporting material such assilica, alumina, magnesia, activated carbon, and the like, or by mixingthe individual components using a fluidized bed granulator. Combinationsof any of the above methods may also be used.

The catalytic materials may optionally comprise a dopant as described inmore detail below. In this respect, doping material(s) may be addedduring preparation of the individual components, after preparation ofthe individual components but before drying of the same, after thedrying step but before calcinations or after calcination. If more thanone doping material is used, each dopant can be added together or oneafter the other to form layers of dopants.

Doping material(s) may also be added as dry components and optionallyball milling can be used to increase mixing. In other embodiments,doping material(s) are added as a liquid (e.g. solution, suspension,slurry, etc.) to the dry individual catalyst components or to theblended catalytic material. The amount of liquid may optionally beadjusted for optimum wetting of the catalyst, which can result inoptimum coverage of catalyst particles by doping material. Mixing and/orball milling can also be used to maximize doping coverage and uniformdistribution. Alternatively, doping material(s) are added as a liquid(e.g. solution, suspension, slurry, etc.) to a suspension or slurry ofthe catalyst in a solvent. Mixing and/or ball milling can be used tomaximize doping coverage and uniform distribution. Incorporation ofdopants can also be achieved using any of the methods describedelsewhere herein.

As noted below, an optional calcination step usually follows an optionaldrying step at T<200 C (typically 60-120 C) in a regular oven or in avacuum oven. Calcination may be performed on the individual componentsof the catalytic material or on the blended catalytic material.Calcination is generally performed in an oven/furnace at a temperaturehigher than the minimum temperature at which at least one of thecomponents decomposes or undergoes a phase transformation and can beperformed in inert atmosphere (e.g. N₂, Ar, He, etc.), oxidizingatmosphere (air, O₂, etc.) or reducing atmosphere (H₂, H₂/N₂, H₂/Ar,etc.). The atmosphere may be a static atmosphere or a gas flow and maybe performed at ambient pressure, at p<1 atm, in vacuum or at p>1 atm.High pressure treatment (at any temperature) may also be used to inducephase transformation including amorphous to crystalline.

Calcination is generally performed in any combination of stepscomprising ramp up, dwell and ramp down. For example, ramp to 500° C.,dwell at 500° C. for 5 h, ramp down to RT. Another example includes rampto 100° C., dwell at 100° C. for 2 h, ramp to 300° C., dwell at 300° C.for 4 h, ramp to 550° C., dwell at 550° C. for 4 h, ramp down to RT.Calcination conditions (pressure, atmosphere type, etc.) can be changedduring the calcination. In some embodiments, calcination is performedbefore preparation of the blended catalytic material (i.e., individualcomponents are calcined), after preparation of the blended catalyticmaterial but before doping, after doping of the individual components orblended catalytic material. Calcination may also be performed multipletimes, e.g. after catalyst preparation and after doping.

The catalytic materials may incorporated into a reactor bed forperforming any number of catalytic reactions (e.g., OCM, ODH and thelike). In this regard, the catalytic material may be packed neat(without diluents) or diluted with an inert material (e.g., sand,silica, alumina, etc.) The catalyst components may be packed uniformlyforming a homogeneous reactor bed.

The particle size of the individual components within a catalyticmaterial may also alter the catalytic activity, and other properties, ofthe same. Accordingly, in one embodiment, the catalyst is milled to atarget average particle size or the catalyst powder is sieved to selecta particular particle size. In some aspects, the catalyst powder may bepressed into pellets and the catalyst pellets can be optionally milledand or sieved to obtain the desired particle size distribution.

In yet another embodiment, the catalysts are packed in bands forming alayered reactor bed. Each layer is composed by either a catalyst of aparticular type, morphology or size or a particular blend of catalysts.In one embodiment, the catalysts blend may have better sinteringproperties, i.e. lower tendency to sinter, then a material in its pureform. Better sintering resistance is expected to increase the catalyst'slifetime and improve the mechanical properties of the reactor bed.

In yet other embodiments, the disclosure provides a catalytic materialcomprising one or more different catalysts. The catalysts may be ananowire as disclosed herein and a different catalyst for example a bulkcatalysts. Mixture of two or more nanowire catalysts are alsocontemplated. The catalytic material may comprise a catalyst, forexample a nanowire catalyst, having good OCM activity and a catalysthaving good activity in the ODH reaction. Either one or both of thesecatalysts may be nanowires as disclosed herein.

On skilled in the art will recognize that various combinations oralternatives of the above methods are possible, and such variations arealso included within the scope of the present disclosure.

5. Dopants

In further embodiments, the disclosure provides nanowires comprising adopant (i.e., doped nanowires). As noted above, dopants or doping agentsare impurities added to or incorporated within a catalyst to optimizecatalytic performance (e.g., increase or decrease catalytic activity).As compared to the undoped catalyst, a doped catalyst may increase ordecrease the selectivity, conversion, and/or yield of a catalyticreaction. In one embodiment, nanowire dopants comprise one or more metalelements, semi-metal elements, non-metal elements or combinationsthereof. The dopant may be present in any form and may be derived fromany suitable source of the element (e.g., chlorides, nitrates, etc.). Insome embodiments, the nanowire dopant is in elemental form. In otherembodiments, the nanowire dopant is in reduced or oxidized form. Inother embodiments, the nanowire dopant comprises an oxide, hydroxide,carbonate, nitrate, acetate, sulfate, formate, oxynitrate, halide,oxyhalide or hydroxyhalide of a metal element, semi-metal element ornon-metal element or combinations thereof.

In one embodiment, the nanowires comprise one or more metal elementsselected from Groups I-7, lanthanides, actinides or combinations thereofin the form of an oxide and further comprise one or more dopants,wherein the one or more dopants comprise metal elements, semi-metalelements, non-metal elements or combinations thereof. In anotherembodiment, the nanowires comprise one or more metal elements selectedfrom group 1 in the form of an oxide and further comprise one or moredopants, wherein the one or more dopants comprise metal elements,semi-metal elements, non-metal elements or combinations thereof. Inanother embodiment, the nanowires comprise one or more metal elementsselected from group 2 in the form of an oxide and further comprise oneor more dopants, wherein the one or more dopants comprise metalelements, semi-metal elements, non-metal elements or combinationsthereof. In another embodiment, the nanowires comprise one or more metalelements selected from group 3 in the form of an oxide and furthercomprise one or more dopants, wherein the one or more dopants comprisemetal elements, semi-metal elements, non-metal elements or combinationsthereof. In another embodiment, the nanowires comprise one or more metalelements selected from group 4 in the form of an oxide and furthercomprise one or more dopants, wherein the one or more dopants comprisemetal elements, semi-metal elements, non-metal elements or combinationsthereof. In another embodiment, the nanowires comprise one or more metalelements selected from group V in the form of an oxide and furthercomprise one or more dopants, wherein the one or more dopants comprisemetal elements, semi-metal elements, non-metal elements or combinationsthereof. In another embodiment, the nanowires comprise one or more metalelements selected from group 6 in the form of an oxide and furthercomprise one or more dopants, wherein the one or more dopants comprisemetal elements, semi-metal elements, non-metal elements or combinationsthereof. In another embodiment, the nanowires comprise one or more metalelements selected from group 7 in the form of an oxide and furthercomprise one or more dopants, wherein the one or more dopants comprisemetal elements, semi-metal elements, non-metal elements or combinationsthereof. In another embodiment, the nanowires comprise one or more metalelements selected from lanthanides in the form of an oxide and furthercomprise one or more dopants, wherein the one or more dopants comprisemetal elements, semi-metal elements, non-metal elements or combinationsthereof. In another embodiment, the nanowires comprise one or more metalelements selected from actinides in the form of an oxide and furthercomprise one or more dopants, wherein the one or more dopants comprisemetal elements, semi-metal elements, non-metal elements or combinationsthereof.

For example, in one embodiment, the nanowire dopant comprises Li,Li₂CO₃, LiOH, Li₂O, LiCl, LiNO₃, Na, Na₂CO₃, NaOH, Na₂O, NaCl, NaNO₃, K,K₂CO₃, KOH, K₂O, KCl, KNO₃, Rb, Rb₂CO₃, RbOH, Rb₂O, RbCl, RbNO₃, Mg,MgCO₃, Mg(OH)₂, MgO, MgCl₂, Mg(NO₃)₂, Ca, CaO, CaCO₃, Ca(OH)₂, CaCl₂,Ca(NO₃)₂, Sr, SrO, SrCO₃, Sr(OH)₂, SrCl₂, Sr(NO₃)₂, Ba, BaO, BaCO₃,Ba(OH)₂, BaCl₂, Ba(NO₃)₂, La, La₂O₃, La(OH)₃, LaCl₃, La(NO₃)₂, Nb,Nb₂O₃, Nb(OH)₃, NbCl₃, Nb(NO₃)₂, Sm, Sm₂O₃, Sm(OH)₃, SmCl₃, Sm(NO₃)₂,Eu, Eu₂O₃, Eu(OH)₃, EuCl₃, Eu(NO₃)₂, Gd, Gd₂O₃, Gd(OH)₃, GdCl₃,Gd(NO₃)₂, Ce, Ce(OH)₄, CeO₂, Ce₂O₃, CeCl₄, Ce(NO₃)₂, Th, ThO₂, ThCl₄,Th(OH)₄, Zr, ZrO₂, ZrCl₄, Zr(OH)₄, ZrOCl₂, ZrO(NO₃)₂, P, phosphorousoxides, phosphorous chlorides, phosphorous carbonates, Ni, nickeloxides, nickel chlorides, nickel carbonates, nickel hydroxides, Nb,niobium oxides, niobium chlorides, niobium carbonates, niobiumhydroxides, Au, gold oxides, gold chlorides, gold carbonates, goldhydroxides, Mo, molybdenum oxides, molybdenum chlorides, molybdenumcarbonates, molybdenum hydroxides, tungsten chlorides, tungstencarbonates, tungsten hydroxides, Cr, chromium oxides, chromiumchlorides, chromium hydroxides, Mn, manganese oxides, manganesechlorides, manganese hydroxides, Zn, ZnO, ZnCl₂, Zn(OH)₂, B, borates,BCl₃, N, nitrogen oxides, nitrates, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb,Dy, Ho, Er, Tm, Yb, Lu, In, Y, Sc, Al, Cu, Cs, Ga, Hf, Fe, Ru, Rh, Be,Co, Sb, V, Ag, Te, Pd, Tb, Ir, Rb or combinations thereof. In otherembodiments, the nanowire dopant comprises Na, Eu, In, Nd, Sm, Ce, Gd,Y, Sc or combinations thereof.

In other embodiments, the nanowire dopant comprises Li, Li₂O, Na, Na₂O,K, K₂O, Mg, MgO, Ca, CaO, Sr, SrO, Ba, BaO, La, La₂O₃, Ce, CeO₂, Ce₂O₃,Th, ThO₂, Zr, ZrO₂, P, phosphorous oxides, Ni, nickel oxides, Nb,niobium oxides, Au, gold oxides, Mo, molybdenum oxides, Cr, chromiumoxides, Mn, manganese oxides, Zn, ZnO, B, borates, N, nitrogen oxides orcombinations thereof. In other embodiments, the nanowire dopantcomprises Li, Na, K, Mg, Ca, Sr, Ba, La, Ce, Th, Zr, P, Ni, Nb, Au, Mo,Cr, Mn, Zn, B, N or combinations thereof. In other embodiments, thenanowire dopant comprises Li₂O, Na₂O, K₂O, MgO, CaO, SrO, BaO, La₂O₃,CeO₂, Ce₂O₃, ThO₂, ZrO₂, phosphorous oxides, nickel oxides, niobiumoxides, gold oxides, molybdenum oxides, chromium oxides, manganeseoxides, ZnO, borates, nitrogen oxides or combinations thereof. Infurther embodiments, the dopant comprises Sr or Li. In other specificembodiments, the nanowire dopant comprises La, Ce, Pr, Nd, Pm, Sm, Eu,Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, In, Y, Sc or combinations thereof. Inother specific embodiments, the nanowire dopant comprises Li, Na, K, Mg,Ca, Ba, Sr, Eu, Sm, Co or Mn.

In certain embodiments, the dopant comprises an element from group 1. Insome embodiments, the dopant comprises lithium. In some embodiments, thedopant comprises sodium. In some embodiments, the dopant comprisespotassium. In some embodiments, the dopant comprises rubidium. In someembodiments, the dopant comprises caesium.

In some embodiments the nanowires comprise a lanthanide element and aredoped with a dopant from group 1, group 2, or combinations thereof. Forexample, in some embodiments, the nanowires comprise a lanthanideelement and are doped with lithium. In other embodiments, the nanowirescomprise a lanthanide element and are doped with sodium. In otherembodiments, the nanowires comprise a lanthanide element and are dopedwith potassium. In other embodiments, the nanowires comprise alanthanide element and are doped with rubidium. In other embodiments,the nanowires comprise a lanthanide element and are doped with caesium.In other embodiments, the nanowires comprise a lanthanide element andare doped with beryllium. In other embodiments, the nanowires comprise alanthanide element and are doped with magnesium. In other embodiments,the nanowires comprise a lanthanide element and are doped with calcium.In other embodiments, the nanowires comprise a lanthanide element andare doped with strontium. In other embodiments, the nanowires comprise alanthanide element and are doped with barium.

In some embodiments the nanowires comprise a transition metal tungstate(e.g., Mn/W and the like) and are doped with a dopant from group 1,group 2, or combinations thereof. For example, in some embodiments, thenanowires comprise a transition metal tungstate and are doped withlithium. In other embodiments, the nanowires comprise a transition metaltungstate and are doped with sodium. In other embodiments, the nanowirescomprise a transition metal tungstate and are doped with potassium. Inother embodiments, the nanowires comprise a transition metal tungstateand are doped with rubidium. In other embodiments, the nanowirescomprise a transition metal tungstate and are doped with caesium. Inother embodiments, the nanowires comprise a transition metal tungstateand are doped with beryllium. In other embodiments, the nanowirescomprise a transition metal tungstate and are doped with magnesium. Inother embodiments, the nanowires comprise a transition metal tungstateand are doped with calcium. In other embodiments, the nanowires comprisea transition metal tungstate and are doped with strontium. In otherembodiments, the nanowires comprises a transition metal tungstate andare doped with barium.

In some embodiments the nanowires comprise Mn/Mg/O and are doped with adopant from group 1, group 2, group 7, group 8, group 9 or group 10 orcombinations thereof. For example, in some embodiments, the nanowirescomprise Mn/Mg/O and are doped with lithium. In other embodiments, thenanowires comprise Mn/Mg/O and are doped with sodium. In otherembodiments, the nanowires comprise Mn/Mg/O and are doped withpotassium. In other embodiments, the nanowires comprise Mn/Mg/O and aredoped with rubidium. In other embodiments, the nanowires compriseMn/Mg/O and are doped with caesium. In other embodiments, the nanowirescomprise Mn/Mg/O and are doped with beryllium. In other embodiments, thenanowires comprise Mn/Mg/O and are doped with magnesium. In otherembodiments, the nanowires comprise Mn/Mg/O and are doped with calcium.In other embodiments, the nanowires comprise Mn/Mg/O and are doped withstrontium. In other embodiments, the nanowires comprise Mn/Mg/O and aredoped with barium.

In yet some other embodiments, the nanowires comprise Mn/Mg/O and aredoped with manganese. In other embodiments, the nanowires compriseMn/Mg/O and are doped with technetium. In other embodiments, thenanowires comprise Mn/Mg/O and are doped with rhenium. In otherembodiments, the nanowires comprise Mn/Mg/O and are doped with bohrium.In other embodiments, the nanowires comprise Mn/Mg/O and are doped withiron. In other embodiments, the nanowires comprise Mn/Mg/O and are dopedwith ruthenium. In other embodiments, the nanowires comprise Mn/Mg/O andare doped with osmium. In other embodiments, the nanowires compriseMn/Mg/O and are doped with hassium. In other embodiments, the nanowirescomprise Mn/Mg/O and are doped with cobalt. In other embodiments, thenanowires comprise Mn/Mg/O and are doped with rhodium. In otherembodiments, the nanowires comprise Mn/Mg/O and are doped with iridium.In other embodiments, the nanowires comprise Mn/Mg/O and are doped withmeitnerium. In other embodiments, the nanowires comprise Mn/Mg/O and aredoped with nickel. In other embodiments, the nanowires comprise Mn/Mg/Oand are doped with palladium. In other embodiments, the nanowirescomprise Mn/Mg/O and are doped with platinum. In other embodiments, thenanowires comprise Mn/Mg/O and are doped with darmistadtium.

It is contemplated that any one or more of the dopants disclosed hereincan be combined with any one of the nanowires disclosed herein to form adoped nanowire comprising one, two, three or more dopants. Tables 1-8below show exemplary doped nanowires in accordance with various specificembodiments. In some embodiments, the doped nanowires shown in tables1-8 are doped with one, two, three or more additional dopants.

TABLE 1 NANOWIRES (NW) DOPED WITH SPECIFIC DOPANTS (DOP) Dop NW Li Na KRb Li₂O Li/ Na/ K/ Rb/ Li₂O Li₂O Li₂O Li₂O Na₂O Li/ Na/ K/ Rb/ Na₂O Na₂ONa₂O Na₂O K₂O Li/ Na/ K/ Rb/ K₂O K₂O K₂O K₂O Rb₂O Li/ Na/ K/ Rb/ Rb₂ORb₂O Rb₂O Rb₂O Cs₂O Li/ Na/ K/ Rb/ Cs₂O Cs₂O Cs₂O Cs₂O BeO Li/ Na/ K/Rb/ BeO BeO BeO BeO MgO Li/ Na/ K/ Rb/ MgO MgO MgO MgO CaO Li/ Na/ K/Rb/ CaO CaO CaO CaO SrO Li/ Na/ K/ Rb/ SrO SrO SrO SrO BaO Li/ Na/ K/Rb/ BaO BaO BaO BaO Sc₂O₃ Li/ Na/ K/ Rb/ Sc₂O₃ Sc₂O₃ Sc₂O₃ Sc₂O₃ Y₂O₃Li/ Na/ K/ Rb/ Y₂O₃ Y₂O₃ Y₂O₃ Y₂O₃ La₂O₃ Li/ Na/ K/ Rb/ La₂O₃ La₂O₃La₂O₃ La₂O₃ CeO₂ Li/ Na/ K/ Rb/ CeO₂ CeO₂ CeO₂ CeO₂ Ce₂O₃ Li/ Na/ K/ Rb/Ce₂O₃ Ce₂O₃ Ce₂O₃ Ce₂O₃ Pr₂O₃ Li/ Na/ K/ Rb/ Pr₂O₃ Pr₂O₃ Pr₂O₃ Pr₂O₃Nd₂O₃ Li/ Na/ K/ Rb/ Nd₂O₃ Nd₂O₃ Nd₂O₃ Nd₂O₃ Sm₂O₃ Li/ Na/ K/ Rb/ Sm₂O₃Sm₂O₃ Sm₂O₃ Sm₂O₃ Eu₂O₃ Li/ Na/ K/ Rb/ Eu₂O₃ Eu₂O₃ Eu₂O₃ Eu₂O₃ Gd₂O₃ Li/Na/ K/ Rb/ Gd₂O₃ Gd₂O₃ Gd₂O₃ Gd₂O₃ Tb₂O₃ Li/ Na/ K/ Rb/ Tb₂O₃ Tb₂O₃Tb₂O₃ Tb₂O₃ TbO₂ Li/ Na/ K/ Rb/ TbO₂ TbO₂ TbO₂ TbO₂ Tb₆O₁₁ Li/ Na/ K/Rb/ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Dy₂O₃ Li/ Na/ K/ Rb/ Dy₂O₃ Dy₂O₃ Dy₂O₃Dy₂O₃ Ho₂O₃ Li/ Na/ K/ Rb/ Ho₂O₃ Ho₂O₃ Ho₂O₃ Ho₂O₃ Er₂O₃ Li/ Na/ K/ Rb/Er₂O₃ Er₂O₃ Er₂O₃ Er₂O₃ Tm₂O₃ Li/ Na/ K/ Rb/ Tm₂O₃ Tm₂O₃ Tm₂O₃ Tm₂O₃Yb₂O₃ Li/ Na/ K/ Rb/ Yb₂O₃ Yb₂O₃ Yb₂O₃ Yb₂O₃ Lu₂O₃ Li/ Na/ K/ Rb/ Lu₂O₃Lu₂O₃ Lu₂O₃ Lu₂O₃ Ac₂O₃ Li/ Na/ K/ Rb/ Ac₂O₃ Ac₂O₃ Ac₂O₃ Ac₂O₃ Th₂O₃ Li/Na/ K/ Rb/ Th₂O₃ Th₂O₃ Th₂O₃ Th₂O₃ ThO₂ Li/ Na/ K/ Rb/ ThO₂ ThO₂ ThO₂ThO₂ Pa₂O₃ Li/ Na/ K/ Rb/ Pa₂O₃ Pa₂O₃ Pa₂O₃ Pa₂O₃ PaO₂ Li/ Na/ K/ Rb/PaO₂ PaO₂ PaO₂ PaO₂ TiO₂ Li/ Na/ K/ Rb/ TiO₂ TiO₂ TiO₂ TiO₂ TiO Li/ Na/K/ Rb/ TiO TiO TiO TiO Ti₂O₃ Li/ Na/ K/ Rb/ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₃OLi/ Na/ K/ Rb/ Ti₃O Ti₃O Ti₃O Ti₃O Ti₂O Li/ Na/ K/ Rb/ Ti₂O Ti₂O Ti₂OTi₂O Ti₃O₅ Li/ Na/ K/ Rb/ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₄O₇ Li/ Na/ K/ Rb/Ti₄O₇ Ti₄O₇ Ti₄O₇ Ti₄O₇ ZrO₂ Li/ Na/ K/ Rb/ ZrO₂ ZrO₂ ZrO₂ ZrO₂ HfO₂ Li/Na/ K/ Rb/ HfO₂ HfO₂ HfO₂ HfO₂ VO Li/ Na/ K/ Rb/ VO VO VO VO V₂O₃ Li/Na/ K/ Rb/ V₂O₃ V₂O₃ V₂O₃ V₂O₃ VO₂ Li/ Na/ K/ Rb/ VO₂ VO₂ VO₂ VO₂ V₂O₅Li/ Na/ K/ Rb/ V₂O₅ V₂O₅ V₂O₅ V₂O₅ V₃O₇ Li/ Na/ K/ Rb/ V₃O₇ V₃O₇ V₃O₇V₃O₇ V₄O₉ Li/ Na/ K/ Rb/ V₄O₉ V₄O₉ V₄O₉ V₄O₉ V₆O₁₃ Li/ Na/ K/ Rb/ V₆O₁₃V₆O₁₃ V₆O₁₃ V₆O₁₃ NbO Li/ Na/ K/ Rb/ NbO NbO NbO NbO NbO₂ Li/ Na/ K/ Rb/NbO₂ NbO₂ NbO₂ NbO₂ Nb₂O₅ Li/ Na/ K/ Rb/ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₈O₁₉Li/ Na/ K/ Rb/ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₁₆O₃₈ Li/ Na/ K/ Rb/Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₂O₂₉ Li/ Na/ K/ Rb/ Nb₁₂O₂₉ Nb₁₂O₂₉Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₄₇O₁₁₆ Li/ Na/ K/ Rb/ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆Nb₄₇O₁₁₆ Ta₂O₅ Li/ Na/ K/ Rb/ Ta₂O₅ Ta₂O₅ Ta₂O₅ Ta₂O₅ CrO Li/ Na/ K/ Rb/CrO CrO CrO CrO Cr₂O₃ Li/ Na/ K/ Rb/ Cr₂O₃ Cr₂O₃ Cr₂O₃ Cr₂O₃ CrO₂ Li/Na/ K/ Rb/ CrO₂ CrO₂ CrO₂ CrO₂ CrO₃ Li/ Na/ K/ Rb/ CrO₃ CrO₃ CrO₃ CrO₃Cr₈O₂₁ Li/ Na/ K/ Rb/ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ MoO₂ Li/ Na/ K/ Rb/MoO₂ MoO₂ MoO₂ MoO₂ MoO₃ Li/ Na/ K/ Rb/ MoO₃ MoO₃ MoO₃ MoO₃ W₂O₃ Li/ Na/K/ Rb/ W₂O₃ W₂O₃ W₂O₃ W₂O₃ WoO₂ Li/ Na/ K/ Rb/ WoO₂ WoO₂ WoO₂ WoO₂ WoO₃Li/ Na/ K/ Rb/ WoO₃ WoO₃ WoO₃ WoO₃ MnO Li/ Na/ K/ Rb/ MnO MnO MnO MnOMn/Mg/O Li/ Na/ K/ Rb/ Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn₃O₄ Li/ Na/ K/Rb/ Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₂O₃ Li/ Na/ K/ Rb/ Mn₂O₃ Mn₂O₃ Mn₂O₃ Mn₂O₃MnO₂ Li/ Na/ K/ Rb/ MnO₂ MnO₂ MnO₂ MnO₂ Mn₂O₇ Li/ Na/ K/ Rb/ Mn₂O₇ Mn₂O₇Mn₂O₇ Mn₂O₇ ReO₂ Li/ Na/ K/ Rb/ ReO₂ ReO₂ ReO₂ ReO₂ ReO₃ Li/ Na/ K/ Rb/ReO₃ ReO₃ ReO₃ ReO₃ Re₂O₇ Li/ Na/ K/ Rb/ Re₂O₇ Re₂O₇ Re₂O₇ Re₂O₇Mg₃Mn₃—B₂O₁₀ Li/ Na/ K/ Rb/ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀Mg₃Mn₃—B₂O₁₀ Mg₃(BO₃)₂ Li/ Na/ K/ Rb/ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂Mg₃(BO₃)₂ Na₂WO₄ Li/ Na/ K/ Rb/ Na₂WO₄ Na₂WO₄ Na₂WO₄ Na₂WO₄ Mg₆MnO₈ Li/Na/ K/ Rb/ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ (Li,Mg)₆—MnO₈ Li/ Na/ K/ Rb/(Li,Mg)₆—MnO₈ (Li,Mg)₆—MnO₈ (Li,Mg)₆—MnO₈ (Li,Mg)₆—MnO₈ Mn₂O₄ Li/ Na/ K/Rb/ Mn₂O₄ Mn₂O₄ Mn₂O₄ Mn₂O₄ Na₄P₂O₇ Li/ Na/ K/ Rb/ Na₄P₂O₇ Na₄P₂O₇Na₄P₂O₇ Na₄P₂O₇ Mo₂O₈ Li/ Na/ K/ Rb/ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mn₃O₄/ Li/Na/ K/ Rb/ WO₄ Mn₃O₄/ Mn₃O₄/ Mn₃O₄/ Mn₃O₄/ WO₄ WO₄ WO₄ WO₄ Na₂WO₄ Li/Na/ K/ Rb/ Na₂WO₄ Na₂WO₄ Na₂WO₄ Na₂WO₄ Zr₂Mo₂O₈ Li/ Na/ K/ Rb/ Zr₂Mo₂O₈Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ NaMnO₄—/ Li/ Na/ K/ Rb/ MgO NaMnO₄—/ NaMnO₄—/NaMnO₄—/ NaMnO₄—/ MgO MgO MgO MgO Na₁₀Mn—W₅O₁₇ Li/ Na/ K/ Rb/Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Dop NW Cs Be Mg CaLi₂O Cs/ Be/ Mg/ Ca/ Li₂O Li₂O Li₂O Li₂O Na₂O Cs/ Be/ Mg/ Ca/ Na₂O Na₂ONa₂O Na₂O K₂O Cs/ Be/ Mg/ Ca/ K₂O K₂O K₂O K₂O Rb₂O Cs/ Be/ Mg/ Ca/ Rb₂ORb₂O Rb₂O Rb₂O Cs₂O Cs/ Be/ Mg/ Ca/ Cs₂O Cs₂O Cs₂O Cs₂O BeO Cs/ Be/ Mg/Ca/ BeO BeO BeO BeO MgO Cs/ Be/ Mg/ Ca/ MgO MgO MgO MgO CaO Cs/ Be/ Mg/Ca/ CaO CaO CaO CaO SrO Cs/ Be/ Mg/ Ca/ SrO SrO SrO SrO BaO Cs/ Be/ Mg/Ca/ BaO BaO BaO BaO Sc₂O₃ Cs/ Be/ Mg/ Ca/ Sc₂O₃ Sc₂O₃ Sc₂O₃ Sc₂O₃ Y₂O₃Cs/ Be/ Mg/ Ca/ Y₂O₃ Y₂O₃ Y₂O₃ Y₂O₃ La₂O₃ Cs/ Be/ Mg/ Ca/ La₂O₃ La₂O₃La₂O₃ La₂O₃ CeO₂ Cs/ Be/ Mg/ Ca/ CeO₂ CeO₂ CeO₂ CeO₂ Ce₂O₃ Cs/ Be/ Mg/Ca/ Ce₂O₃ Ce₂O₃ Ce₂O₃ Ce₂O₃ Pr₂O₃ Cs/ Be/ Mg/ Ca/ Pr₂O₃ Pr₂O₃ Pr₂O₃Pr₂O₃ Nd₂O₃ Cs/ Be/ Mg/ Ca/ Nd₂O₃ Nd₂O₃ Nd₂O₃ Nd₂O₃ Sm₂O₃ Cs/ Be/ Mg/Ca/ Sm₂O₃ Sm₂O₃ Sm₂O₃ Sm₂O₃ Eu₂O₃ Cs/ Be/ Mg/ Ca/ Eu₂O₃ Eu₂O₃ Eu₂O₃Eu₂O₃ Gd₂O₃ Cs/ Be/ Mg/ Ca/ Gd₂O₃ Gd₂O₃ Gd₂O₃ Gd₂O₃ Tb₂O₃ Cs/ Be/ Mg/Ca/ Tb₂O₃ Tb₂O₃ Tb₂O₃ Tb₂O₃ TbO₂ Cs/ Be/ Mg/ Ca/ TbO₂ TbO₂ TbO₂ TbO₂Tb₆O₁₁ Cs/ Be/ Mg/ Ca/ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Dy₂O₃ Cs/ Be/ Mg/ Ca/Dy₂O₃ Dy₂O₃ Dy₂O₃ Dy₂O₃ Ho₂O₃ Cs/ Be/ Mg/ Ca/ Ho₂O₃ Ho₂O₃ Ho₂O₃ Ho₂O₃Er₂O₃ Cs/ Be/ Mg/ Ca/ Er₂O₃ Er₂O₃ Er₂O₃ Er₂O₃ Tm₂O₃ Cs/ Be/ Mg/ Ca/Tm₂O₃ Tm₂O₃ Tm₂O₃ Tm₂O₃ Yb₂O₃ Cs/ Be/ Mg/ Ca/ Yb₂O₃ Yb₂O₃ Yb₂O₃ Yb₂O₃Lu₂O₃ Cs/ Be/ Mg/ Ca/ Lu₂O₃ Lu₂O₃ Lu₂O₃ Lu₂O₃ Ac₂O₃ Cs/ Be/ Mg/ Ca/Ac₂O₃ Ac₂O₃ Ac₂O₃ Ac₂O₃ Th₂O₃ Cs/ Be/ Mg/ Ca/ Th₂O₃ Th₂O₃ Th₂O₃ Th₂O₃ThO₂ Cs/ Be/ Mg/ Ca/ ThO₂ ThO₂ ThO₂ ThO₂ Pa₂O₃ Cs/ Be/ Mg/ Ca/ Pa₂O₃Pa₂O₃ Pa₂O₃ Pa₂O₃ PaO₂ Cs/ Be/ Mg/ Ca/ PaO₂ PaO₂ PaO₂ PaO₂ TiO₂ Cs/ Be/Mg/ Ca/ TiO₂ TiO₂ TiO₂ TiO₂ TiO Cs/ Be/ Mg/ Ca/ TiO TiO TiO TiO Ti₂O₃Cs/ Be/ Mg/ Ca/ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₃O Cs/ Be/ Mg/ Ca/ Ti₃O Ti₃OTi₃O Ti₃O Ti₂O Cs/ Be/ Mg/ Ca/ Ti₂O Ti₂O Ti₂O Ti₂O Ti₃O₅ Cs/ Be/ Mg/ Ca/Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₄O₇ Cs/ Be/ Mg/ Ca/ Ti₄O₇ Ti₄O₇ Ti₄O₇ Ti₄O₇ZrO₂ Cs/ Be/ Mg/ Ca/ ZrO₂ ZrO₂ ZrO₂ ZrO₂ HfO₂ Cs/ Be/ Mg/ Ca/ HfO₂ HfO₂HfO₂ HfO₂ VO Cs/ Be/ Mg/ Ca/ VO VO VO VO V₂O₃ Cs/ Be/ Mg/ Ca/ V₂O₃ V₂O₃V₂O₃ V₂O₃ VO₂ Cs/ Be/ Mg/ Ca/ VO₂ VO₂ VO₂ VO₂ V₂O₅ Cs/ Be/ Mg/ Ca/ V₂O₅V₂O₅ V₂O₅ V₂O₅ V₃O₇ Cs/ Be/ Mg/ Ca/ V₃O₇ V₃O₇ V₃O₇ V₃O₇ V₄O₉ Cs/ Be/ Mg/Ca/ V₄O₉ V₄O₉ V₄O₉ V₄O₉ V₆O₁₃ Cs/ Be/ Mg/ Ca/ V₆O₁₃ V₆O₁₃ V₆O₁₃ V₆O₁₃NbO Cs/ Be/ Mg/ Ca/ NbO NbO NbO NbO NbO₂ Cs/ Be/ Mg/ Ca/ NbO₂ NbO₂ NbO₂NbO₂ Nb₂O₅ Cs/ Be/ Mg/ Ca/ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₈O₁₉ Cs/ Be/ Mg/Ca/ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₁₆O₃₈ Cs/ Be/ Mg/ Ca/ Nb₁₆O₃₈ Nb₁₆O₃₈Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₂O₂₉ Cs/ Be/ Mg/ Ca/ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉Nb₄₇O₁₁₆ Cs/ Be/ Mg/ Ca/ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Ta₂O₅ Cs/Be/ Mg/ Ca/ Ta₂O₅ Ta₂O₅ Ta₂O₅ Ta₂O₅ CrO Cs/ Be/ Mg/ Ca/ CrO CrO CrO CrOCr₂O₃ Cs/ Be/ Mg/ Ca/ Cr₂O₃ Cr₂O₃ Cr₂O₃ Cr₂O₃ CrO₂ Cs/ Be/ Mg/ Ca/ CrO₂CrO₂ CrO₂ CrO₂ CrO₃ Cs/ Be/ Mg/ Ca/ CrO₃ CrO₃ CrO₃ CrO₃ Cr₈O₂₁ Cs/ Be/Mg/ Ca/ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ MoO₂ Cs/ Be/ Mg/ Ca/ MoO₂ MoO₂ MoO₂MoO₂ MoO₃ Cs/ Be/ Mg/ Ca/ MoO₃ MoO₃ MoO₃ MoO₃ W₂O₃ Cs/ Be/ Mg/ Ca/ W₂O₃W₂O₃ W₂O₃ W₂O₃ WoO₂ Cs/ Be/ Mg/ Ca/ WoO₂ WoO₂ WoO₂ WoO₂ WoO₃ Cs/ Be/ Mg/Ca/ WoO₃ WoO₃ WoO₃ WoO₃ MnO Cs/ Be/ Mg/ Ca/ MnO MnO MnO MnO Mn/Mg/O Cs/Be/ Mg/ Ca/ Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn₃O₄ Cs/ Be/ Mg/ Ca/ Mn₃O₄Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₂O₃ Cs/ Be/ Mg/ Ca/ Mn₂O₃ Mn₂O₃ Mn₂O₃ Mn₂O₃ MnO₂ Cs/Be/ Mg/ Ca/ MnO₂ MnO₂ MnO₂ MnO₂ Mn₂O₇ Cs/ Be/ Mg/ Ca/ Mn₂O₇ Mn₂O₇ Mn₂O₇Mn₂O₇ ReO₂ Cs/ Be/ Mg/ Ca/ ReO₂ ReO₂ ReO₂ ReO₂ ReO₃ Cs/ Be/ Mg/ Ca/ ReO₃ReO₃ ReO₃ ReO₃ Re₂O₇ Cs/ Be/ Mg/ Ca/ Re₂O₇ Re₂O₇ Re₂O₇ Re₂O₇Mg₃Mn₃—B₂O₁₀ Cs/ Be/ Mg/ Ca/ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀Mg₃Mn₃—B₂O₁₀ Mg₃(BO₃)₂ Cs/ Be/ Mg/ Ca/ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂Mg₃(BO₃)₂ Na₂WO₄ Cs/ Be/ Mg/ Ca/ Na₂WO₄ Na₂WO₄ Na₂WO₄ Na₂WO₄ Mg₆MnO₈ Cs/Be/ Mg/ Ca/ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ (Li,Mg)₆—MnO₈ Cs/ Be/ Mg/Ca/ (Li,Mg)₆—MnO₈ (Li,Mg)₆—MnO₈ (Li,Mg)₆—MnO₈ (Li,Mg)₆—MnO₈ Mn₂O₄ Cs/Be/ Mg/ Ca/ Mn₂O₄ Mn₂O₄ Mn₂O₄ Mn₂O₄ Na₄P₂O₇ Cs/ Be/ Mg/ Ca/ Na₄P₂O₇Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇ Mo₂O₈ Cs/ Be/ Mg/ Ca/ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mo₂O₈Mn₃O₄/ Cs/ Be/ Mg/ Ca/ WO₄ Mn₃O₄/ Mn₃O₄/ Mn₃O₄/ Mn₃O₄/ WO₄ WO₄ WO₄ WO₄Na₂WO₄ Cs/ Be/ Mg/ Ca/ Na₂WO₄ Na₂WO₄ Na₂WO₄ Na₂WO₄ Zr₂Mo₂O₈ Cs/ Be/ Mg/Ca/ Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ NaMnO₄—/ Cs/ Be/ Mg/ Ca/ MgONaMnO₄—/ NaMnO₄—/ NaMnO₄—/ NaMnO₄—/ MgO MgO MgO MgO Na₁₀Mn—W₅O₁₇ Cs/ Be/Mg/ Ca/ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇

TABLE 2 NANOWIRES (NW) DOPED WITH SPECIFIC DOPANTS (DOP) Dop NW Sr Ba BP Li₂O Sr/ Ba/ B/ P/ Li₂O Li₂O Li₂O Li₂O Na₂O Sr/ Ba/ B/ P/ Na₂O Na₂ONa₂O Na₂O K₂O Sr/ Ba/ B/ P/ K₂O K₂O K₂O K₂O Rb₂O Sr/ Ba/ B/ P/ Rb₂O Rb₂ORb₂O Rb₂O Cs₂O Sr/ Ba/ B/ P/ Cs₂O Cs₂O Cs₂O Cs₂O BeO Sr/ Ba/ B/ P/ BeOBeO BeO BeO MgO Sr/ Ba/ B/ P/ MgO MgO MgO MgO CaO Sr/ Ba/ B/ P/ CaO CaOCaO CaO SrO Sr/ Ba/ B/ P/ SrO SrO SrO SrO BaO Sr/ Ba/ B/ P/ BaO BaO BaOBaO Sc₂O₃ Sr/ Ba/ B/ P/ Sc₂O₃ Sc₂O₃ Sc₂O₃ Sc₂O₃ Y₂O₃ Sr/ Ba/ B/ P/ Y₂O₃Y₂O₃ Y₂O₃ Y₂O₃ La₂O₃ Sr/ Ba/ B/ P/ La₂O₃ La₂O₃ La₂O₃ La₂O₃ CeO₂ Sr/ Ba/B/ P/ CeO₂ CeO₂ CeO₂ CeO₂ Ce₂O₃ Sr/ Ba/ B/ P/ Ce₂O₃ Ce₂O₃ Ce₂O₃ Ce₂O₃Pr₂O₃ Sr/ Ba/ B/ P/ Pr₂O₃ Pr₂O₃ Pr₂O₃ Pr₂O₃ Nd₂O₃ Sr/ Ba/ B/ P/ Nd₂O₃Nd₂O₃ Nd₂O₃ Nd₂O₃ Sm₂O₃ Sr/ Ba/ B/ P/ Sm₂O₃ Sm₂O₃ Sm₂O₃ Sm₂O₃ Eu₂O₃ Sr/Ba/ B/ P/ Eu₂O₃ Eu₂O₃ Eu₂O₃ Eu₂O₃ Gd₂O₃ Sr/ Ba/ B/ P/ Gd₂O₃ Gd₂O₃ Gd₂O₃Gd₂O₃ Tb₂O₃ Sr/ Ba/ B/ P/ Tb₂O₃ Tb₂O₃ Tb₂O₃ Tb₂O₃ TbO₂ Sr/ Ba/ B/ P/TbO₂ TbO₂ TbO₂ TbO₂ Tb₆O₁₁ Sr/ Ba/ B/ P/ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁Dy₂O₃ Sr/ Ba/ B/ P/ Dy₂O₃ Dy₂O₃ Dy₂O₃ Dy₂O₃ Ho₂O₃ Sr/ Ba/ B/ P/ Ho₂O₃Ho₂O₃ Ho₂O₃ Ho₂O₃ Er₂O₃ Sr/ Ba/ B/ P/ Er₂O₃ Er₂O₃ Er₂O₃ Er₂O₃ Tm₂O₃ Sr/Ba/ B/ P/ Tm₂O₃ Tm₂O₃ Tm₂O₃ Tm₂O₃ Yb₂O₃ Sr/ Ba/ B/ P/ Yb₂O₃ Yb₂O₃ Yb₂O₃Yb₂O₃ Lu₂O₃ Sr/ Ba/ B/ P/ Lu₂O₃ Lu₂O₃ Lu₂O₃ Lu₂O₃ Ac₂O₃ Sr/ Ba/ B/ P/Ac₂O₃ Ac₂O₃ Ac₂O₃ Ac₂O₃ Th₂O₃ Sr/ Ba/ B/ P/ Th₂O₃ Th₂O₃ Th₂O₃ Th₂O₃ ThO₂Sr/ Ba/ B/ P/ ThO₂ ThO₂ ThO₂ ThO₂ Pa₂O₃ Sr/ Ba/ B/ P/ Pa₂O₃ Pa₂O₃ Pa₂O₃Pa₂O₃ PaO₂ Sr/ Ba/ B/ P/ PaO₂ PaO₂ PaO₂ PaO₂ TiO₂ Sr/ Ba/ B/ P/ TiO₂TiO₂ TiO₂ TiO₂ TiO Sr/ Ba/ B/ P/ TiO TiO TiO TiO Ti₂O₃ Sr/ Ba/ B/ P/Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₃O Sr/ Ba/ B/ P/ Ti₃O Ti₃O Ti₃O Ti₃O Ti₂O Sr/Ba/ B/ P/ Ti₂O Ti₂O Ti₂O Ti₂O Ti₃O₅ Sr/ Ba/ B/ P/ Ti₃O₅ Ti₃O₅ Ti₃O₅Ti₃O₅ Ti₄O₇ Sr/ Ba/ B/ P/ Ti₄O₇ Ti₄O₇ Ti₄O₇ Ti₄O₇ ZrO₂ Sr/ Ba/ B/ P/ZrO₂ ZrO₂ ZrO₂ ZrO₂ HfO₂ Sr/ Ba/ B/ P/ HfO₂ HfO₂ HfO₂ HfO₂ VO Sr/ Ba/ B/P/ VO VO VO VO V₂O₃ Sr/ Ba/ B/ P/ V₂O₃ V₂O₃ V₂O₃ V₂O₃ VO₂ Sr/ Ba/ B/ P/VO₂ VO₂ VO₂ VO₂ V₂O₅ Sr/ Ba/ B/ P/ V₂O₅ V₂O₅ V₂O₅ V₂O₅ V₃O₇ Sr/ Ba/ B/P/ V₃O₇ V₃O₇ V₃O₇ V₃O₇ V₄O₉ Sr/ Ba/ B/ P/ V₄O₉ V₄O₉ V₄O₉ V₄O₉ V₆O₁₃ Sr/Ba/ B/ P/ V₆O₁₃ V₆O₁₃ V₆O₁₃ V₆O₁₃ NbO Sr/ Ba/ B/ P/ NbO NbO NbO NbO NbO₂Sr/ Ba/ B/ P/ NbO₂ NbO₂ NbO₂ NbO₂ Nb₂O₅ Sr/ Ba/ B/ P/ Nb₂O₅ Nb₂O₅ Nb₂O₅Nb₂O₅ Nb₈O₁₉ Sr/ Ba/ B/ P/ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₁₆O₃₈ Sr/ Ba/B/ P/ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₂O₂₉ Sr/ Ba/ B/ P/ Nb₁₂O₂₉Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₄₇O₁₁₆ Sr/ Ba/ B/ P/ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Ta₂O₅ Sr/ Ba/ B/ P/ Ta₂O₅ Ta₂O₅ Ta₂O₅ Ta₂O₅ CrO Sr/Ba/ B/ P/ CrO CrO CrO CrO Cr₂O₃ Sr/ Ba/ B/ P/ Cr₂O₃ Cr₂O₃ Cr₂O₃ Cr₂O₃CrO₂ Sr/ Ba/ B/ P/ CrO₂ CrO₂ CrO₂ CrO₂ CrO₃ Sr/ Ba/ B/ P/ CrO₃ CrO₃ CrO₃CrO₃ Cr₈O₂₁ Sr/ Ba/ B/ P/ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ MoO₂ Sr/ Ba/ B/ P/MoO₂ MoO₂ MoO₂ MoO₂ MoO₃ Sr/ Ba/ B/ P/ MoO₃ MoO₃ MoO₃ MoO₃ W₂O₃ Sr/ Ba/B/ P/ W₂O₃ W₂O₃ W₂O₃ W₂O₃ WoO₂ Sr/ Ba/ B/ P/ WoO₂ WoO₂ WoO₂ WoO₂ WoO₃Sr/ Ba/ B/ P/ WoO₃ WoO₃ WoO₃ WoO₃ MnO Sr/ Ba/ B/ P/ MnO MnO MnO MnOMn/Mg/O Sr/ Ba/ B/ P/ Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn₃O₄ Sr/ Ba/ B/P/ Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₂O₃ Sr/ Ba/ B/ P/ Mn₂O₃ Mn₂O₃ Mn₂O₃ Mn₂O₃MnO₂ Sr/ Ba/ B/ P/ MnO₂ MnO₂ MnO₂ MnO₂ Mn₂O₇ Sr/ Ba/ B/ P/ Mn₂O₇ Mn₂O₇Mn₂O₇ Mn₂O₇ ReO₂ Sr/ Ba/ B/ P/ ReO₂ ReO₂ ReO₂ ReO₂ ReO₃ Sr/ Ba/ B/ P/ReO₃ ReO₃ ReO₃ ReO₃ Re₂O₇ Sr/ Ba/ B/ P/ Re₂O₇ Re₂O₇ Re₂O₇ Re₂O₇Mg₃Mn₃—B₂O₁₀ Sr/ Ba/ B/ P/ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀Mg₃Mn₃—B₂O₁₀ Mg₃(BO₃)₂ Sr/ Ba/ B/ P/ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂Mg₃(BO₃)₂ NaWO₄ Sr/ Ba/ B/ P/ NaWO₄ NaWO₄ NaWO₄ NaWO₄ Mg₆MnO₈ Sr/ Ba/ B/P/ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ (Li,Mg)₆MnO₈ Sr/ Ba/ B/ P/(Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈ Mn₂O₄ Sr/ Ba/ B/ P/Mn₂O₄ Mn₂O₄ Mn₂O₄ Mn₂O₄ Na₄P₂O₇ Sr/ Ba/ B/ P/ Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇Na₄P₂O₇ Mo₂O₈ Sr/ Ba/ B/ P/ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mn₃O₄/WO₄ Sr/ Ba/ B/P/ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Na₂WO₄ Sr/ Ba/ B/ P/ Na₂WO₄Na₂WO₄ Na₂WO₄ Na₂WO₄ Zr₂Mo₂O₈ Sr/ Ba/ B/ P/ Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈Zr₂Mo₂O₈ NaMnO₄/MgO Sr/ Ba/ B/ P/ NaMnO₄/MgO NaMnO₄/MgO NaMnO₄/MgONaMnO₄/MgO Na₁₀Mn—W₅O₁₇ Sr/ Ba/ B/ P/ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Dop NW S F Cl Li₂O S/ F/ Cl/ Li₂O Li₂O Li₂ONa₂O S/ F/ Cl/ Na₂O Na₂O Na₂O K₂O S/ F/ Cl/ K₂O K₂O K₂O Rb₂O S/ F/ Cl/Rb₂O Rb₂O Rb₂O Cs₂O S/ F/ Cl/ Cs₂O Cs₂O Cs₂O BeO S/ F/ Cl/ BeO BeO BeOMgO S/ F/ Cl/ MgO MgO MgO CaO S/ F/ Cl/ CaO CaO CaO SrO S/ F/ Cl/ SrOSrO SrO BaO S/ F/ Cl/ BaO BaO BaO Sc₂O₃ S/ F/ Cl/ Sc₂O₃ Sc₂O₃ Sc₂O₃ Y₂O₃S/ F/ Cl/ Y₂O₃ Y₂O₃ Y₂O₃ La₂O₃ S/ F/ Cl/ La₂O₃ La₂O₃ La₂O₃ CeO₂ S/ F/Cl/ CeO₂ CeO₂ CeO₂ Ce₂O₃ S/ F/ Cl/ Ce₂O₃ Ce₂O₃ Ce₂O₃ Pr₂O₃ S/ F/ Cl/Pr₂O₃ Pr₂O₃ Pr₂O₃ Nd₂O₃ S/ F/ Cl/ Nd₂O₃ Nd₂O₃ Nd₂O₃ Sm₂O₃ S/ F/ Cl/Sm₂O₃ Sm₂O₃ Sm₂O₃ Eu₂O₃ S/ F/ Cl/ Eu₂O₃ Eu₂O₃ Eu₂O₃ Gd₂O₃ S/ F/ Cl/Gd₂O₃ Gd₂O₃ Gd₂O₃ Tb₂O₃ S/ F/ Cl/ Tb₂O₃ Tb₂O₃ Tb₂O₃ TbO₂ S/ F/ Cl/ TbO₂TbO₂ TbO₂ Tb₆O₁₁ S/ F/ Cl/ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Dy₂O₃ S/ F/ Cl/ Dy₂O₃Dy₂O₃ Dy₂O₃ Ho₂O₃ S/ F/ Cl/ Ho₂O₃ Ho₂O₃ Ho₂O₃ Er₂O₃ S/ F/ Cl/ Er₂O₃Er₂O₃ Er₂O₃ Tm₂O₃ S/ F/ Cl/ Tm₂O₃ Tm₂O₃ Tm₂O₃ Yb₂O₃ S/ F/ Cl/ Yb₂O₃Yb₂O₃ Yb₂O₃ Lu₂O₃ S/ F/ Cl/ Lu₂O₃ Lu₂O₃ Lu₂O₃ Ac₂O₃ S/ F/ Cl/ Ac₂O₃Ac₂O₃ Ac₂O₃ Th₂O₃ S/ F/ Cl/ Th₂O₃ Th₂O₃ Th₂O₃ ThO₂ S/ F/ Cl/ ThO₂ ThO₂ThO₂ Pa₂O₃ S/ F/ Cl/ Pa₂O₃ Pa₂O₃ Pa₂O₃ PaO₂ S/ F/ Cl/ PaO₂ PaO₂ PaO₂TiO₂ S/ F/ Cl/ TiO₂ TiO₂ TiO₂ TiO S/ F/ Cl/ TiO TiO TiO Ti₂O₃ S/ F/ Cl/Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₃O S/ F/ Cl/ Ti₃O Ti₃O Ti₃O Ti₂O S/ F/ Cl/ Ti₂O Ti₂OTi₂O Ti₃O₅ S/ F/ Cl/ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₄O₇ S/ F/ Cl/ Ti₄O₇ Ti₄O₇ Ti₄O₇ZrO₂ S/ F/ Cl/ ZrO₂ ZrO₂ ZrO₂ HfO₂ S/ F/ Cl/ HfO₂ HfO₂ HfO₂ VO S/ F/ Cl/VO VO VO V₂O₃ S/ F/ Cl/ V₂O₃ V₂O₃ V₂O₃ VO₂ S/ F/ Cl/ VO₂ VO₂ VO₂ V₂O₅ S/F/ Cl/ V₂O₅ V₂O₅ V₂O₅ V₃O₇ S/ F/ Cl/ V₃O₇ V₃O₇ V₃O₇ V₄O₉ S/ F/ Cl/ V₄O₉V₄O₉ V₄O₉ V₆O₁₃ S/ F/ Cl/ V₆O₁₃ V₆O₁₃ V₆O₁₃ NbO S/ F/ Cl/ NbO NbO NbONbO₂ S/ F/ Cl/ NbO₂ NbO₂ NbO₂ Nb₂O₅ S/ F/ Cl/ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₈O₁₉S/ F/ Cl/ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₁₆O₃₈ S/ F/ Cl/ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈Nb₁₂O₂₉ S/ F/ Cl/ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₄₇O₁₁₆ S/ F/ Cl/ Nb₄₇O₁₁₆Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Ta₂O₅ S/ F/ Cl/ Ta₂O₅ Ta₂O₅ Ta₂O₅ CrO S/ F/ Cl/ CrOCrO CrO Cr₂O₃ S/ F/ Cl/ Cr₂O₃ Cr₂O₃ Cr₂O₃ CrO₂ S/ F/ Cl/ CrO₂ CrO₂ CrO₂CrO₃ S/ F/ Cl/ CrO₃ CrO₃ CrO₃ Cr₈O₂₁ S/ F/ Cl/ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ MoO₂S/ F/ Cl/ MoO₂ MoO₂ MoO₂ MoO₃ S/ F/ Cl/ MoO₃ MoO₃ MoO₃ W₂O₃ S/ F/ Cl/W₂O₃ W₂O₃ W₂O₃ WoO₂ S/ F/ Cl/ WoO₂ WoO₂ WoO₂ WoO₃ S/ F/ Cl/ WoO₃ WoO₃WoO₃ MnO S/ F/ Cl/ MnO MnO MnO Mn/Mg/O S/ F/ Cl/ Mn/Mg/O Mn/Mg/O Mn/Mg/OMn₃O₄ S/ F/ Cl/ Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₂O₃ S/ F/ Cl/ Mn₂O₃ Mn₂O₃ Mn₂O₃ MnO₂S/ F/ Cl/ MnO₂ MnO₂ MnO₂ Mn₂O₇ S/ F/ Cl/ Mn₂O₇ Mn₂O₇ Mn₂O₇ ReO₂ S/ F/Cl/ ReO₂ ReO₂ ReO₂ ReO₃ S/ F/ Cl/ ReO₃ ReO₃ ReO₃ Re₂O₇ S/ F/ Cl/ Re₂O₇Re₂O₇ Re₂O₇ Mg₃Mn₃—B₂O₁₀ S/ F/ Cl/ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀Mg₃Mn₃—B₂O₁₀ Mg₃(BO₃)₂ S/ F/ Cl/ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂ NaWO₄ S/F/ Cl/ NaWO₄ NaWO₄ NaWO₄ Mg₆MnO₈ S/ F/ Cl/ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈(Li,Mg)₆MnO₈ S/ F/ Cl/ (Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈ Mn₂O₄ S/F/ Cl/ Mn₂O₄ Mn₂O₄ Mn₂O₄ Na₄P₂O₇ S/ F/ Cl/ Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇ Mo₂O₈S/ F/ Cl/ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mn₃O₄/WO₄ S/ F/ Cl/ Mn₃O₄/WO₄ Mn₃O₄/WO₄Mn₃O₄/WO₄ Na₂WO₄ S/ F/ Cl/ Na₂WO₄ Na₂WO₄ Na₂WO₄ Zr₂Mo₂O₈ S/ F/ Cl/Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ NaMnO₄/MgO S/ F/ Cl/ NaMnO₄/MgO NaMnO₄/MgONaMnO₄/MgO Na₁₀Mn—W₅O₁₇ S/ F/ Cl/ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇

TABLE 3 NANOWIRES (NW) DOPED WITH SPECIFIC DOPANTS (DOP) Dop NW La Ce PrNd Li₂O La/ Ce/ Pr/ Nd/ Li₂O Li₂O Li₂O Li₂O Na₂O La/ Ce/ Pr/ Nd/ Na₂ONa₂O Na₂O Na₂O K₂O La/ Ce/ Pr/ Nd/ K₂O K₂O K₂O K₂O Rb₂O La/ Ce/ Pr/ Nd/Rb₂O Rb₂O Rb₂O Rb₂O Cs₂O La/ Ce/ Pr/ Nd/ Cs₂O Cs₂O Cs₂O Cs₂O BeO La/ Ce/Pr/ Nd/ BeO BeO BeO BeO MgO La/ Ce/ Pr/ Nd/ MgO MgO MgO MgO CaO La/ Ce/Pr/ Nd/ CaO CaO CaO CaO SrO La/ Ce/ Pr/ Nd/ SrO SrO SrO SrO BaO La/ Ce/Pr/ Nd/ BaO BaO BaO BaO Sc₂O₃ La/ Ce/ Pr/ Nd/ Sc₂O₃ Sc₂O₃ Sc₂O₃ Sc₂O₃Y₂O₃ La/ Ce/ Pr/ Nd/ Y₂O₃ Y₂O₃ Y₂O₃ Y₂O₃ La₂O₃ La/ Ce/ Pr/ Nd/ La₂O₃La₂O₃ La₂O₃ La₂O₃ CeO₂ La/ Ce/ Pr/ Nd/ CeO₂ CeO₂ CeO₂ CeO₂ Ce₂O₃ La/ Ce/Pr/ Nd/ Ce₂O₃ Ce₂O₃ Ce₂O₃ Ce₂O₃ Pr₂O₃ La/ Ce/ Pr/ Nd/ Pr₂O₃ Pr₂O₃ Pr₂O₃Pr₂O₃ Nd₂O₃ La/ Ce/ Pr/ Nd/ Nd₂O₃ Nd₂O₃ Nd₂O₃ Nd₂O₃ Sm₂O₃ La/ Ce/ Pr/Nd/ Sm₂O₃ Sm₂O₃ Sm₂O₃ Sm₂O₃ Eu₂O₃ La/ Ce/ Pr/ Nd/ Eu₂O₃ Eu₂O₃ Eu₂O₃Eu₂O₃ Gd₂O₃ La/ Ce/ Pr/ Nd/ Gd₂O₃ Gd₂O₃ Gd₂O₃ Gd₂O₃ Tb₂O₃ La/ Ce/ Pr/Nd/ Tb₂O₃ Tb₂O₃ Tb₂O₃ Tb₂O₃ TbO₂ La/ Ce/ Pr/ Nd/ TbO₂ TbO₂ TbO₂ TbO₂Tb₆O₁₁ La/ Ce/ Pr/ Nd/ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Dy₂O₃ La/ Ce/ Pr/ Nd/Dy₂O₃ Dy₂O₃ Dy₂O₃ Dy₂O₃ Ho₂O₃ La/ Ce/ Pr/ Nd/ Ho₂O₃ Ho₂O₃ Ho₂O₃ Ho₂O₃Er₂O₃ La/ Ce/ Pr/ Nd/ Er₂O₃ Er₂O₃ Er₂O₃ Er₂O₃ Tm₂O₃ La/ Ce/ Pr/ Nd/Tm₂O₃ Tm₂O₃ Tm₂O₃ Tm₂O₃ Yb₂O₃ La/ Ce/ Pr/ Nd/ Yb₂O₃ Yb₂O₃ Yb₂O₃ Yb₂O₃Lu₂O₃ La/ Ce/ Pr/ Nd/ Lu₂O₃ Lu₂O₃ Lu₂O₃ Lu₂O₃ Ac₂O₃ La/ Ce/ Pr/ Nd/Ac₂O₃ Ac₂O₃ Ac₂O₃ Ac₂O₃ Th₂O₃ La/ Ce/ Pr/ Nd/ Th₂O₃ Th₂O₃ Th₂O₃ Th₂O₃ThO₂ La/ Ce/ Pr/ Nd/ ThO₂ ThO₂ ThO₂ ThO₂ Pa₂O₃ La/ Ce/ Pr/ Nd/ Pa₂O₃Pa₂O₃ Pa₂O₃ Pa₂O₃ PaO₂ La/ Ce/ Pr/ Nd/ PaO₂ PaO₂ PaO₂ PaO₂ TiO₂ La/ Ce/Pr/ Nd/ TiO₂ TiO₂ TiO₂ TiO₂ TiO La/ Ce/ Pr/ Nd/ TiO TiO TiO TiO Ti₂O₃La/ Ce/ Pr/ Nd/ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₃O La/ Ce/ Pr/ Nd/ Ti₃O Ti₃OTi₃O Ti₃O Ti₂O La/ Ce/ Pr/ Nd/ Ti₂O Ti₂O Ti₂O Ti₂O Ti₃O₅ La/ Ce/ Pr/ Nd/Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₄O₇ La/ Ce/ Pr/ Nd/ Ti₄O₇ Ti₄O₇ Ti₄O₇ Ti₄O₇ZrO₂ La/ Ce/ Pr/ Nd/ ZrO₂ ZrO₂ ZrO₂ ZrO₂ HfO₂ La/ Ce/ Pr/ Nd/ HfO₂ HfO₂HfO₂ HfO₂ VO La/ Ce/ Pr/ Nd/ VO VO VO VO V₂O₃ La/ Ce/ Pr/ Nd/ V₂O₃ V₂O₃V₂O₃ V₂O₃ VO₂ La/ Ce/ Pr/ Nd/ VO₂ VO₂ VO₂ VO₂ V₂O₅ La/ Ce/ Pr/ Nd/ V₂O₅V₂O₅ V₂O₅ V₂O₅ V₃O₇ La/ Ce/ Pr/ Nd/ V₃O₇ V₃O₇ V₃O₇ V₃O₇ V₄O₉ La/ Ce/ Pr/Nd/ V₄O₉ V₄O₉ V₄O₉ V₄O₉ V₆O₁₃ La/ Ce/ Pr/ Nd/ V₆O₁₃ V₆O₁₃ V₆O₁₃ V₆O₁₃NbO La/ Ce/ Pr/ Nd/ NbO NbO NbO NbO NbO₂ La/ Ce/ Pr/ Nd/ NbO₂ NbO₂ NbO₂NbO₂ Nb₂O₅ La/ Ce/ Pr/ Nd/ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₈O₁₉ La/ Ce/ Pr/Nd/ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₁₆O₃₈ La/ Ce/ Pr/ Nd/ Nb₁₆O₃₈ Nb₁₆O₃₈Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₂O₂₉ La/ Ce/ Pr/ Nd/ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉Nb₄₇O₁₁₆ La/ Ce/ Pr/ Nd/ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Ta₂O₅ La/Ce/ Pr/ Nd/ Ta₂O₅ Ta₂O₅ Ta₂O₅ Ta₂O₅ CrO La/ Ce/ Pr/ Nd/ CrO CrO CrO CrOCr₂O₃ La/ Ce/ Pr/ Nd/ Cr₂O₃ Cr₂O₃ Cr₂O₃ Cr₂O₃ CrO₂ La/ Ce/ Pr/ Nd/ CrO₂CrO₂ CrO₂ CrO₂ CrO₃ La/ Ce/ Pr/ Nd/ CrO₃ CrO₃ CrO₃ CrO₃ Cr₈O₂₁ La/ Ce/Pr/ Nd/ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ MoO₂ La/ Ce/ Pr/ Nd/ MoO₂ MoO₂ MoO₂MoO₂ MoO₃ La/ Ce/ Pr/ Nd/ MoO₃ MoO₃ MoO₃ MoO₃ W₂O₃ La/ Ce/ Pr/ Nd/ W₂O₃W₂O₃ W₂O₃ W₂O₃ WoO₂ La/ Ce/ Pr/ Nd/ WoO₂ WoO₂ WoO₂ WoO₂ WoO₃ La/ Ce/ Pr/Nd/ WoO₃ WoO₃ WoO₃ WoO₃ MnO La/ Ce/ Pr/ Nd/ MnO MnO MnO MnO Mn/Mg/O La/Ce/ Pr/ Nd/ Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn₃O₄ La/ Ce/ Pr/ Nd/ Mn₃O₄Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₂O₃ La/ Ce/ Pr/ Nd/ Mn₂O₃ Mn₂O₃ Mn₂O₃ Mn₂O₃ MnO₂ La/Ce/ Pr/ Nd/ MnO₂ MnO₂ MnO₂ MnO₂ Mn₂O₇ La/ Ce/ Pr/ Nd/ Mn₂O₇ Mn₂O₇ Mn₂O₇Mn₂O₇ ReO₂ La/ Ce/ Pr/ Nd/ ReO₂ ReO₂ ReO₂ ReO₂ ReO₃ La/ Ce/ Pr/ Nd/ ReO₃ReO₃ ReO₃ ReO₃ Re₂O₇ La/ Ce/ Pr/ Nd/ Re₂O₇ Re₂O₇ Re₂O₇ Re₂O₇Mg₃Mn₃—B₂O₁₀ La/ Ce/ Pr/ Nd/ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀Mg₃Mn₃—B₂O₁₀ Mg₃(BO₃)₂ La/ Ce/ Pr/ Nd/ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂Mg₃(BO₃)₂ NaWO₄ La/ Ce/ Pr/ Nd/ NaWO₄ NaWO₄ NaWO₄ NaWO₄ Mg₆MnO₈ La/ Ce/Pr/ Nd/ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ (Li,Mg)₆MnO₈ La/ Ce/ Pr/ Nd/(Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈ Mn₂O₄ La/ Ce/ Pr/Nd/ Mn₂O₄ Mn₂O₄ Mn₂O₄ Mn₂O₄ Na₄P₂O₇ La/ Ce/ Pr/ Nd/ Na₄P₂O₇ Na₄P₂O₇Na₄P₂O₇ Na₄P₂O₇ Mo₂O₈ La/ Ce/ Pr/ Nd/ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mn₃O₄/WO₄La/ Ce/ Pr/ Nd/ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Na₂WO₄ La/ Ce/Pr/ Nd/ Na₂WO₄ Na₂WO₄ Na₂WO₄ Na₂WO₄ Zr₂Mo₂O₈ La/ Ce/ Pr/ Nd/ Zr₂Mo₂O₈Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ NaMnO₄—/ La/ Ce/ Pr/ Nd/ MgO NaMnO₄—/NaMnO₄—/ NaMnO₄—/ NaMnO₄—/ MgO MgO MgO MgO Na₁₀Mn—W₅O₁₇ La/ Ce/ Pr/ Nd/Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Dop NW Pm Sm Eu GdLi₂O Pm/ Sm/ Eu/ Gd/ Li₂O Li₂O Li₂O Li₂O Na₂O Pm/ Sm/ Eu/ Gd/ Na₂O Na₂ONa₂O Na₂O K₂O Pm/ Sm/ Eu/ Gd/ K₂O K₂O K₂O K₂O Rb₂O Pm/ Sm/ Eu/ Gd/ Rb₂ORb₂O Rb₂O Rb₂O Cs₂O Pm/ Sm/ Eu/ Gd/ Cs₂O Cs₂O Cs₂O Cs₂O BeO Pm/ Sm/ Eu/Gd/ BeO BeO BeO BeO MgO Pm/ Sm/ Eu/ Gd/ MgO MgO MgO MgO CaO Pm/ Sm/ Eu/Gd/ CaO CaO CaO CaO SrO Pm/ Sm/ Eu/ Gd/ SrO SrO SrO SrO BaO Pm/ Sm/ Eu/Gd/ BaO BaO BaO BaO Sc₂O₃ Pm/ Sm/ Eu/ Gd/ Sc₂O₃ Sc₂O₃ Sc₂O₃ Sc₂O₃ Y₂O₃Pm/ Sm/ Eu/ Gd/ Y₂O₃ Y₂O₃ Y₂O₃ Y₂O₃ La₂O₃ Pm/ Sm/ Eu/ Gd/ La₂O₃ La₂O₃La₂O₃ La₂O₃ CeO₂ Pm/ Sm/ Eu/ Gd/ CeO₂ CeO₂ CeO₂ CeO₂ Ce₂O₃ Pm/ Sm/ Eu/Gd/ Ce₂O₃ Ce₂O₃ Ce₂O₃ Ce₂O₃ Pr₂O₃ Pm/ Sm/ Eu/ Gd/ Pr₂O₃ Pr₂O₃ Pr₂O₃Pr₂O₃ Nd₂O₃ Pm/ Sm/ Eu/ Gd/ Nd₂O₃ Nd₂O₃ Nd₂O₃ Nd₂O₃ Sm₂O₃ Pm/ Sm/ Eu/Gd/ Sm₂O₃ Sm₂O₃ Sm₂O₃ Sm₂O₃ Eu₂O₃ Pm/ Sm/ Eu/ Gd/ Eu₂O₃ Eu₂O₃ Eu₂O₃Eu₂O₃ Gd₂O₃ Pm/ Sm/ Eu/ Gd/ Gd₂O₃ Gd₂O₃ Gd₂O₃ Gd₂O₃ Tb₂O₃ Pm/ Sm/ Eu/Gd/ Tb₂O₃ Tb₂O₃ Tb₂O₃ Tb₂O₃ TbO₂ Pm/ Sm/ Eu/ Gd/ TbO₂ TbO₂ TbO₂ TbO₂Tb₆O₁₁ Pm/ Sm/ Eu/ Gd/ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Dy₂O₃ Pm/ Sm/ Eu/ Gd/Dy₂O₃ Dy₂O₃ Dy₂O₃ Dy₂O₃ Ho₂O₃ Pm/ Sm/ Eu/ Gd/ Ho₂O₃ Ho₂O₃ Ho₂O₃ Ho₂O₃Er₂O₃ Pm/ Sm/ Eu/ Gd/ Er₂O₃ Er₂O₃ Er₂O₃ Er₂O₃ Tm₂O₃ Pm/ Sm/ Eu/ Gd/Tm₂O₃ Tm₂O₃ Tm₂O₃ Tm₂O₃ Yb₂O₃ Pm/ Sm/ Eu/ Gd/ Yb₂O₃ Yb₂O₃ Yb₂O₃ Yb₂O₃Lu₂O₃ Pm/ Sm/ Eu/ Gd/ Lu₂O₃ Lu₂O₃ Lu₂O₃ Lu₂O₃ Ac₂O₃ Pm/ Sm/ Eu/ Gd/Ac₂O₃ Ac₂O₃ Ac₂O₃ Ac₂O₃ Th₂O₃ Pm/ Sm/ Eu/ Gd/ Th₂O₃ Th₂O₃ Th₂O₃ Th₂O₃ThO₂ Pm/ Sm/ Eu/ Gd/ ThO₂ ThO₂ ThO₂ ThO₂ Pa₂O₃ Pm/ Sm/ Eu/ Gd/ Pa₂O₃Pa₂O₃ Pa₂O₃ Pa₂O₃ PaO₂ Pm/ Sm/ Eu/ Gd/ PaO₂ PaO₂ PaO₂ PaO₂ TiO₂ Pm/ Sm/Eu/ Gd/ TiO₂ TiO₂ TiO₂ TiO₂ TiO Pm/ Sm/ Eu/ Gd/ TiO TiO TiO TiO Ti₂O₃Pm/ Sm/ Eu/ Gd/ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₃O Pm/ Sm/ Eu/ Gd/ Ti₃O Ti₃OTi₃O Ti₃O Ti₂O Pm/ Sm/ Eu/ Gd/ Ti₂O Ti₂O Ti₂O Ti₂O Ti₃O₅ Pm/ Sm/ Eu/ Gd/Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₄O₇ Pm/ Sm/ Eu/ Gd/ Ti₄O₇ Ti₄O₇ Ti₄O₇ Ti₄O₇ZrO₂ Pm/ Sm/ Eu/ Gd/ ZrO₂ ZrO₂ ZrO₂ ZrO₂ HfO₂ Pm/ Sm/ Eu/ Gd/ HfO₂ HfO₂HfO₂ HfO₂ VO Pm/ Sm/ Eu/ Gd/ VO VO VO VO V₂O₃ Pm/ Sm/ Eu/ Gd/ V₂O₃ V₂O₃V₂O₃ V₂O₃ VO₂ Pm/ Sm/ Eu/ Gd/ VO₂ VO₂ VO₂ VO₂ V₂O₅ Pm/ Sm/ Eu/ Gd/ V₂O₅V₂O₅ V₂O₅ V₂O₅ V₃O₇ Pm/ Sm/ Eu/ Gd/ V₃O₇ V₃O₇ V₃O₇ V₃O₇ V₄O₉ Pm/ Sm/ Eu/Gd/ V₄O₉ V₄O₉ V₄O₉ V₄O₉ V₆O₁₃ Pm/ Sm/ Eu/ Gd/ V₆O₁₃ V₆O₁₃ V₆O₁₃ V₆O₁₃NbO Pm/ Sm/ Eu/ Gd/ NbO NbO NbO NbO NbO₂ Pm/ Sm/ Eu/ Gd/ NbO₂ NbO₂ NbO₂NbO₂ Nb₂O₅ Pm/ Sm/ Eu/ Gd/ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₈O₁₉ Pm/ Sm/ Eu/Gd/ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₁₆O₃₈ Pm/ Sm/ Eu/ Gd/ Nb₁₆O₃₈ Nb₁₆O₃₈Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₂O₂₉ Pm/ Sm/ Eu/ Gd/ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉Nb₄₇O₁₁₆ Pm/ Sm/ Eu/ Gd/ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Ta₂O₅ Pm/Sm/ Eu/ Gd/ Ta₂O₅ Ta₂O₅ Ta₂O₅ Ta₂O₅ CrO Pm/ Sm/ Eu/ Gd/ CrO CrO CrO CrOCr₂O₃ Pm/ Sm/ Eu/ Gd/ Cr₂O₃ Cr₂O₃ Cr₂O₃ Cr₂O₃ CrO₂ Pm/ Sm/ Eu/ Gd/ CrO₂CrO₂ CrO₂ CrO₂ CrO₃ Pm/ Sm/ Eu/ Gd/ CrO₃ CrO₃ CrO₃ CrO₃ Cr₈O₂₁ Pm/ Sm/Eu/ Gd/ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ MoO₂ Pm/ Sm/ Eu/ Gd/ MoO₂ MoO₂ MoO₂MoO₂ MoO₃ Pm/ Sm/ Eu/ Gd/ MoO₃ MoO₃ MoO₃ MoO₃ W₂O₃ Pm/ Sm/ Eu/ Gd/ W₂O₃W₂O₃ W₂O₃ W₂O₃ WoO₂ Pm/ Sm/ Eu/ Gd/ WoO₂ WoO₂ WoO₂ WoO₂ WoO₃ Pm/ Sm/ Eu/Gd/ WoO₃ WoO₃ WoO₃ WoO₃ MnO Pm/ Sm/ Eu/ Gd/ MnO MnO MnO MnO Mn/Mg/O Pm/Sm/ Eu/ Gd/ Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn₃O₄ Pm/ Sm/ Eu/ Gd/ Mn₃O₄Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₂O₃ Pm/ Sm/ Eu/ Gd/ Mn₂O₃ Mn₂O₃ Mn₂O₃ Mn₂O₃ MnO₂ Pm/Sm/ Eu/ Gd/ MnO₂ MnO₂ MnO₂ MnO₂ Mn₂O₇ Pm/ Sm/ Eu/ Gd/ Mn₂O₇ Mn₂O₇ Mn₂O₇Mn₂O₇ ReO₂ Pm/ Sm/ Eu/ Gd/ ReO₂ ReO₂ ReO₂ ReO₂ ReO₃ Pm/ Sm/ Eu/ Gd/ ReO₃ReO₃ ReO₃ ReO₃ Re₂O₇ Pm/ Sm/ Eu/ Gd/ Re₂O₇ Re₂O₇ Re₂O₇ Re₂O₇Mg₃Mn₃—B₂O₁₀ Pm/ Sm/ Eu/ Gd/ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀Mg₃Mn₃—B₂O₁₀ Mg₃(BO₃)₂ Pm/ Sm/ Eu/ Gd/ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂Mg₃(BO₃)₂ NaWO₄ Pm/ Sm/ Eu/ Gd/ NaWO₄ NaWO₄ NaWO₄ NaWO₄ Mg₆MnO₈ Pm/ Sm/Eu/ Gd/ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ (Li,Mg)₆MnO₈ Pm/ Sm/ Eu/ Gd/(Li,Mg)₆MnO8 (Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈ Mn₂O₄ Pm/ Sm/ Eu/Gd/ Mn₂O₄ Mn₂O₄ Mn₂O₄ Mn₂O₄ Na₄P₂O₇ Pm/ Sm/ Eu/ Gd/ Na₄P₂O₇ Na₄P₂O₇Na₄P₂O₇ Na₄P₂O₇ Mo₂O₈ Pm/ Sm/ Eu/ Gd/ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mn₃O₄/WO₄Pm/ Sm/ Eu/ Gd/ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Na₂WO₄ Pm/ Sm/Eu/ Gd/ Na₂WO₄ Na₂WO₄ Na₂WO₄ Na₂WO₄ Zr₂Mo₂O₈ Pm/ Sm/ Eu/ Gd/ Zr₂Mo₂O₈Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ NaMnO₄—/ Pm/ Sm/ Eu/ Gd/ MgO NaMnO₄—/NaMnO₄—/ NaMnO₄—/ NaMnO₄—/ MgO MgO MgO MgO Na₁₀Mn—W₅O₁₇ Pm/ Sm/ Eu/ Gd/Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇

TABLE 4 NANOWIRES (NW) DOPED WITH SPECIFIC DOPANTS (DOP) Dop NW Tb Dy HoEr Li₂O Tb/ Dy/ Ho/ Er/ Li₂O Li₂O Li₂O Li₂O Na₂O Tb/ Dy/ Ho/ Er/ Na₂ONa₂O Na₂O Na₂O K₂O Tb/ Dy/ Ho/ Er/ K₂O K₂O K₂O K₂O Rb₂O Tb/ Dy/ Ho/ Er/Rb₂O Rb₂O Rb₂O Rb₂O Cs₂O Tb/ Dy/ Ho/ Er/ Cs₂O Cs₂O Cs₂O Cs₂O BeO Tb/ Dy/Ho/ Er/ BeO BeO BeO BeO MgO Tb/ Dy/ Ho/ Er/ MgO MgO MgO MgO CaO Tb/ Dy/Ho/ Er/ CaO CaO CaO CaO SrO Tb/ Dy/ Ho/ Er/ SrO SrO SrO SrO BaO Tb/ Dy/Ho/ Er/ BaO BaO BaO BaO Sc₂O₃ Tb/ Dy/ Ho/ Er/ Sc₂O₃ Sc₂O₃ Sc₂O₃ Sc₂O₃Y₂O₃ Tb/ Dy/ Ho/ Er/ Y₂O₃ Y₂O₃ Y₂O₃ Y₂O₃ La₂O₃ Tb/ Dy/ Ho/ Er/ La₂O₃La₂O₃ La₂O₃ La₂O₃ CeO₂ Tb/ Dy/ Ho/ Er/ CeO₂ CeO₂ CeO₂ CeO₂ Ce₂O₃ Tb/ Dy/Ho/ Er/ Ce₂O₃ Ce₂O₃ Ce₂O₃ Ce₂O₃ Pr₂O₃ Tb/ Dy/ Ho/ Er/ Pr₂O₃ Pr₂O₃ Pr₂O₃Pr₂O₃ Nd₂O₃ Tb/ Dy/ Ho/ Er/ Nd₂O₃ Nd₂O₃ Nd₂O₃ Nd₂O₃ Sm₂O₃ Tb/ Dy/ Ho/Er/ Sm₂O₃ Sm₂O₃ Sm₂O₃ Sm₂O₃ Eu₂O₃ Tb/ Dy/ Ho/ Er/ Eu₂O₃ Eu₂O₃ Eu₂O₃Eu₂O₃ Gd₂O₃ Tb/ Dy/ Ho/ Er/ Gd₂O₃ Gd₂O₃ Gd₂O₃ Gd₂O₃ Tb₂O₃ Tb/ Dy/ Ho/Er/ Tb₂O₃ Tb₂O₃ Tb₂O₃ Tb₂O₃ TbO₂ Tb/ Dy/ Ho/ Er/ TbO₂ TbO₂ TbO₂ TbO₂Tb₆O₁₁ Tb/ Dy/ Ho/ Er/ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Dy₂O₃ Tb/ Dy/ Ho/ Er/Dy₂O₃ Dy₂O₃ Dy₂O₃ Dy₂O₃ Ho₂O₃ Tb/ Dy/ Ho/ Er/ Ho₂O₃ Ho₂O₃ Ho₂O₃ Ho₂O₃Er₂O₃ Tb/ Dy/ Ho/ Er/ Er₂O₃ Er₂O₃ Er₂O₃ Er₂O₃ Tm₂O₃ Tb/ Dy/ Ho/ Er/Tm₂O₃ Tm₂O₃ Tm₂O₃ Tm₂O₃ Yb₂O₃ Tb/ Dy/ Ho/ Er/ Yb₂O₃ Yb₂O₃ Yb₂O₃ Yb₂O₃Lu₂O₃ Tb/ Dy/ Ho/ Er/ Lu₂O₃ Lu₂O₃ Lu₂O₃ Lu₂O₃ Ac₂O₃ Tb/ Dy/ Ho/ Er/Ac₂O₃ Ac₂O₃ Ac₂O₃ Ac₂O₃ Th₂O₃ Tb/ Dy/ Ho/ Er/ Th₂O₃ Th₂O₃ Th₂O₃ Th₂O₃ThO₂ Tb/ Dy/ Ho/ Er/ ThO₂ ThO₂ ThO₂ ThO₂ Pa₂O₃ Tb/ Dy/ Ho/ Er/ Pa₂O₃Pa₂O₃ Pa₂O₃ Pa₂O₃ PaO₂ Tb/ Dy/ Ho/ Er/ PaO₂ PaO₂ PaO₂ PaO₂ TiO₂ Tb/ Dy/Ho/ Er/ TiO₂ TiO₂ TiO₂ TiO₂ TiO Tb/ Dy/ Ho/ Er/ TiO TiO TiO TiO Ti₂O₃Tb/ Dy/ Ho/ Er/ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₃O Tb/ Dy/ Ho/ Er/ Ti₃O Ti₃OTi₃O Ti₃O Ti₂O Tb/ Dy/ Ho/ Er/ Ti₂O Ti₂O Ti₂O Ti₂O Ti₃O₅ Tb/ Dy/ Ho/ Er/Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₄O₇ Tb/ Dy/ Ho/ Er/ Ti₄O₇ Ti₄O₇ Ti₄O₇ Ti₄O₇ZrO₂ Tb/ Dy/ Ho/ Er/ ZrO₂ ZrO₂ ZrO₂ ZrO₂ HfO₂ Tb/ Dy/ Ho/ Er/ HfO₂ HfO₂HfO₂ HfO₂ VO Tb/ Dy/ Ho/ Er/ VO VO VO VO V₂O₃ Tb/ Dy/ Ho/ Er/ V₂O₃ V₂O₃V₂O₃ V₂O₃ VO₂ Tb/ Dy/ Ho/ Er/ VO₂ VO₂ VO₂ VO₂ V₂O₅ Tb/ Dy/ Ho/ Er/ V₂O₅V₂O₅ V₂O₅ V₂O₅ V₃O₇ Tb/ Dy/ Ho/ Er/ V₃O₇ V₃O₇ V₃O₇ V₃O₇ V₄O₉ Tb/ Dy/ Ho/Er/ V₄O₉ V₄O₉ V₄O₉ V₄O₉ V₆O₁₃ Tb/ Dy/ Ho/ Er/ V₆O₁₃ V₆O₁₃ V₆O₁₃ V₆O₁₃NbO Tb/ Dy/ Ho/ Er/ NbO NbO NbO NbO NbO₂ Tb/ Dy/ Ho/ Er/ NbO₂ NbO₂ NbO₂NbO₂ Nb₂O₅ Tb/ Dy/ Ho/ Er/ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₈O₁₉ Tb/ Dy/ Ho/Er/ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₁₆O₃₈ Tb/ Dy/ Ho/ Er/ Nb₁₆O₃₈ Nb₁₆O₃₈Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₂O₂₉ Tb/ Dy/ Ho/ Er/ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉Nb₄₇O₁₁₆ Tb/ Dy/ Ho/ Er/ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Ta₂O₅ Tb/Dy/ Ho/ Er/ Ta₂O₅ Ta₂O₅ Ta₂O₅ Ta₂O₅ CrO Tb/ Dy/ Ho/ Er/ CrO CrO CrO CrOCr₂O₃ Tb/ Dy/ Ho/ Er/ Cr₂O₃ Cr₂O₃ Cr₂O₃ Cr₂O₃ CrO₂ Tb/ Dy/ Ho/ Er/ CrO₂CrO₂ CrO₂ CrO₂ CrO₃ Tb/ Dy/ Ho/ Er/ CrO₃ CrO₃ CrO₃ CrO₃ Cr₈O₂₁ Tb/ Dy/Ho/ Er/ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ MoO₂ Tb/ Dy/ Ho/ Er/ MoO₂ MoO₂ MoO₂MoO₂ MoO₃ Tb/ Dy/ Ho/ Er/ MoO₃ MoO₃ MoO₃ MoO₃ W₂O₃ Tb/ Dy/ Ho/ Er/ W₂O₃W₂O₃ W₂O₃ W₂O₃ WoO₂ Tb/ Dy/ Ho/ Er/ WoO₂ WoO₂ WoO₂ WoO₂ WoO₃ Tb/ Dy/ Ho/Er/ WoO₃ WoO₃ WoO₃ WoO₃ MnO Tb/ Dy/ Ho/ Er/ MnO MnO MnO MnO Mn/Mg/O Tb/Dy/ Ho/ Er/ Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn₃O₄ Tb/ Dy/ Ho/ Er/ Mn₃O₄Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₂O₃ Tb/ Dy/ Ho/ Er/ Mn₂O₃ Mn₂O₃ Mn₂O₃ Mn₂O₃ MnO₂ Tb/Dy/ Ho/ Er/ MnO₂ MnO₂ MnO₂ MnO₂ Mn₂O₇ Tb/ Dy/ Ho/ Er/ Mn₂O₇ Mn₂O₇ Mn₂O₇Mn₂O₇ ReO₂ Tb/ Dy/ Ho/ Er/ ReO₂ ReO₂ ReO₂ ReO₂ ReO₃ Tb/ Dy/ Ho/ Er/ ReO₃ReO₃ ReO₃ ReO₃ Re₂O₇ Tb/ Dy/ Ho/ Er/ Re₂O₇ Re₂O₇ Re₂O₇ Re₂O₇Mg₃Mn₃—B₂O₁₀ Tb/ Dy/ Ho/ Er/ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀Mg₃Mn₃—B₂O₁₀ Mg₃(BO₃)₂ Tb/ Dy/ Ho/ Er/ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂Mg₃(BO₃)₂ NaWO₄ Tb/ Dy/ Ho/ Er/ NaWO₄ NaWO₄ NaWO₄ NaWO₄ Mg₆MnO₈ Tb/ Dy/Ho/ Er/ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ Mn₂O₄ Tb/ Dy/ Ho/ Er/ Mn₂O₄Mn₂O₄ Mn₂O₄ Mn₂O₄ (Li,Mg)₆MnO₈ Tb/ Dy/ Ho/ Er/ (Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈(Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈ Na₄P₂O₇ Tb/ Dy/ Ho/ Er/ Na₄P₂O₇ Na₄P₂O₇Na₄P₂O₇ Na₄P₂O₇ Mo₂O₈ Tb/ Dy/ Ho/ Er/ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mn₃O₄/WO₄Tb/ Dy/ Ho/ Er/ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Na₂WO₄ Tb/ Dy/Ho/ Er/ Na₂WO₄ Na₂WO₄ Na₂WO₄ Na₂WO₄ Zr₂Mo₂O₈ Tb/ Dy/ Ho/ Er/ Zr₂Mo₂O₈Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ NaMnO₄—/ Tb/ Dy/ Ho/ Er/ MgO NaMnO₄—/NaMnO₄—/ NaMnO₄—/ NaMnO₄—/ MgO MgO MgO MgO Na₁₀Mn—W₅O₁₇ Tb/ Dy/ Ho/ Er/Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Dop NW Tm Yb Lu InLi₂O Tm/ Yb/ Lu/ In/ Li₂O Li₂O Li₂O Li₂O Na₂O Tm/ Yb/ Lu/ In/ Na₂O Na₂ONa₂O Na₂O K₂O Tm/ Yb/ Lu/ In/ K₂O K₂O K₂O K₂O Rb₂O Tm/ Yb/ Lu/ In/ Rb₂ORb₂O Rb₂O Rb₂O Cs₂O Tm/ Yb/ Lu/ In/ Cs₂O Cs₂O Cs₂O Cs₂O BeO Tm/ Yb/ Lu/In/ BeO BeO BeO BeO MgO Tm/ Yb/ Lu/ In/ MgO MgO MgO MgO CaO Tm/ Yb/ Lu/In/ CaO CaO CaO CaO SrO Tm/ Yb/ Lu/ In/ SrO SrO SrO SrO BaO Tm/ Yb/ Lu/In/ BaO BaO BaO BaO Sc₂O₃ Tm/ Yb/ Lu/ In/ Sc₂O₃ Sc₂O₃ Sc₂O₃ Sc₂O₃ Y₂O₃Tm/ Yb/ Lu/ In/ Y₂O₃ Y₂O₃ Y₂O₃ Y₂O₃ La₂O₃ Tm/ Yb/ Lu/ In/ La₂O₃ La₂O₃La₂O₃ La₂O₃ CeO₂ Tm/ Yb/ Lu/ In/ CeO₂ CeO₂ CeO₂ CeO₂ Ce₂O₃ Tm/ Yb/ Lu/In/ Ce₂O₃ Ce₂O₃ Ce₂O₃ Ce₂O₃ Pr₂O₃ Tm/ Yb/ Lu/ In/ Pr₂O₃ Pr₂O₃ Pr₂O₃Pr₂O₃ Nd₂O₃ Tm/ Yb/ Lu/ In/ Nd₂O₃ Nd₂O₃ Nd₂O₃ Nd₂O₃ Sm₂O₃ Tm/ Yb/ Lu/In/ Sm₂O₃ Sm₂O₃ Sm₂O₃ Sm₂O₃ Eu₂O₃ Tm/ Yb/ Lu/ In/ Eu₂O₃ Eu₂O₃ Eu₂O₃Eu₂O₃ Gd₂O₃ Tm/ Yb/ Lu/ In/ Gd₂O₃ Gd₂O₃ Gd₂O₃ Gd₂O₃ Tb₂O₃ Tm/ Yb/ Lu/In/ Tb₂O₃ Tb₂O₃ Tb₂O₃ Tb₂O₃ TbO₂ Tm/ Yb/ Lu/ In/ TbO₂ TbO₂ TbO₂ TbO₂Tb₆O₁₁ Tm/ Yb/ Lu/ In/ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Dy₂O₃ Tm/ Yb/ Lu/ In/Dy₂O₃ Dy₂O₃ Dy₂O₃ Dy₂O₃ Ho₂O₃ Tm/ Yb/ Lu/ In/ Ho₂O₃ Ho₂O₃ Ho₂O₃ Ho₂O₃Er₂O₃ Tm/ Yb/ Lu/ In/ Er₂O₃ Er₂O₃ Er₂O₃ Er₂O₃ Tm₂O₃ Tm/ Yb/ Lu/ In/Tm₂O₃ Tm₂O₃ Tm₂O₃ Tm₂O₃ Yb₂O₃ Tm/ Yb/ Lu/ In/ Yb₂O₃ Yb₂O₃ Yb₂O₃ Yb₂O₃Lu₂O₃ Tm/ Yb/ Lu/ In/ Lu₂O₃ Lu₂O₃ Lu₂O₃ Lu₂O₃ Ac₂O₃ Tm/ Yb/ Lu/ In/Ac₂O₃ Ac₂O₃ Ac₂O₃ Ac₂O₃ Th₂O₃ Tm/ Yb/ Lu/ In/ Th₂O₃ Th₂O₃ Th₂O₃ Th₂O₃ThO₂ Tm/ Yb/ Lu/ In/ ThO₂ ThO₂ ThO₂ ThO₂ Pa₂O₃ Tm/ Yb/ Lu/ In/ Pa₂O₃Pa₂O₃ Pa₂O₃ Pa₂O₃ PaO₂ Tm/ Yb/ Lu/ In/ PaO₂ PaO₂ PaO₂ PaO₂ TiO₂ Tm/ Yb/Lu/ In/ TiO₂ TiO₂ TiO₂ TiO₂ TiO Tm/ Yb/ Lu/ In/ TiO TiO TiO TiO Ti₂O₃Tm/ Yb/ Lu/ In/ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₃O Tm/ Yb/ Lu/ In/ Ti₃O Ti₃OTi₃O Ti₃O Ti₂O Tm/ Yb/ Lu/ In/ Ti₂O Ti₂O Ti₂O Ti₂O Ti₃O₅ Tm/ Yb/ Lu/ In/Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₄O₇ Tm/ Yb/ Lu/ In/ Ti₄O₇ Ti₄O₇ Ti₄O₇ Ti₄O₇ZrO₂ Tm/ Yb/ Lu/ In/ ZrO₂ ZrO₂ ZrO₂ ZrO₂ HfO₂ Tm/ Yb/ Lu/ In/ HfO₂ HfO₂HfO₂ HfO₂ VO Tm/ Yb/ Lu/ In/ VO VO VO VO V₂O₃ Tm/ Yb/ Lu/ In/ V₂O₃ V₂O₃V₂O₃ V₂O₃ VO₂ Tm/ Yb/ Lu/ In/ VO₂ VO₂ VO₂ VO₂ V₂O₅ Tm/ Yb/ Lu/ In/ V₂O₅V₂O₅ V₂O₅ V₂O₅ V₃O₇ Tm/ Yb/ Lu/ In/ V₃O₇ V₃O₇ V₃O₇ V₃O₇ V₄O₉ Tm/ Yb/ Lu/In/ V₄O₉ V₄O₉ V₄O₉ V₄O₉ V₆O₁₃ Tm/ Yb/ Lu/ In/ V₆O₁₃ V₆O₁₃ V₆O₁₃ V₆O₁₃NbO Tm/ Yb/ Lu/ In/ NbO NbO NbO NbO NbO₂ Tm/ Yb/ Lu/ In/ NbO₂ NbO₂ NbO₂NbO₂ Nb₂O₅ Tm/ Yb/ Lu/ In/ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₈O₁₉ Tm/ Yb/ Lu/In/ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₁₆O₃₈ Tm/ Yb/ Lu/ In/ Nb₁₆O₃₈ Nb₁₆O₃₈Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₂O₂₉ Tm/ Yb/ Lu/ In/ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉Nb₄₇O₁₁₆ Tm/ Yb/ Lu/ In/ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Ta₂O₅ Tm/Yb/ Lu/ In/ Ta₂O₅ Ta₂O₅ Ta₂O₅ Ta₂O₅ CrO Tm/ Yb/ Lu/ In/ CrO CrO CrO CrOCr₂O₃ Tm/ Yb/ Lu/ In/ Cr₂O₃ Cr₂O₃ Cr₂O₃ Cr₂O₃ CrO₂ Tm/ Yb/ Lu/ In/ CrO₂CrO₂ CrO₂ CrO₂ CrO₃ Tm/ Yb/ Lu/ In/ CrO₃ CrO₃ CrO₃ CrO₃ Cr₈O₂₁ Tm/ Yb/Lu/ In/ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ MoO₂ Tm/ Yb/ Lu/ In/ MoO₂ MoO₂ MoO₂MoO₂ MoO₃ Tm/ Yb/ Lu/ In/ MoO₃ MoO₃ MoO₃ MoO₃ W₂O₃ Tm/ Yb/ Lu/ In/ W₂O₃W₂O₃ W₂O₃ W₂O₃ WoO₂ Tm/ Yb/ Lu/ In/ WoO₂ WoO₂ WoO₂ WoO₂ WoO₃ Tm/ Yb/ Lu/In/ WoO₃ WoO₃ WoO₃ WoO₃ MnO Tm/ Yb/ Lu/ In/ MnO MnO MnO MnO Mn/Mg/O Tm/Yb/ Lu/ In/ Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn₃O₄ Tm/ Yb/ Lu/ In/ Mn₃O₄Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₂O₃ Tm/ Yb/ Lu/ In/ Mn₂O₃ Mn₂O₃ Mn₂O₃ Mn₂O₃ MnO₂ Tm/Yb/ Lu/ In/ MnO₂ MnO₂ MnO₂ MnO₂ Mn₂O₇ Tm/ Yb/ Lu/ In/ Mn₂O₇ Mn₂O₇ Mn₂O₇Mn₂O₇ ReO₂ Tm/ Yb/ Lu/ In/ ReO₂ ReO₂ ReO₂ ReO₂ ReO₃ Tm/ Yb/ Lu/ In/ ReO₃ReO₃ ReO₃ ReO₃ Re₂O₇ Tm/ Yb/ Lu/ In/ Re₂O₇ Re₂O₇ Re₂O₇ Re₂O₇Mg₃Mn₃—B₂O₁₀ Tm/ Yb/ Lu/ In/ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀Mg₃Mn₃—B₂O₁₀ Mg₃(BO₃)₂ Tm/ Yb/ Lu/ In/ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂Mg₃(BO₃)₂ NaWO₄ Tm/ Yb/ Lu/ In/ NaWO₄ NaWO₄ NaWO₄ NaWO₄ Mg₆MnO₈ Tm/ Yb/Lu/ In/ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ Mn₂O₄ Tm/ Yb/ Lu/ In/ Mn₂O₄Mn₂O₄ Mn₂O₄ Mn₂O₄ (Li,Mg)₆MnO₈ Tm/ Yb/ Lu/ In/ (Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈(Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈ Na₄P₂O₇ Tm/ Yb/ Lu/ In/ Na₄P₂O₇ Na₄P₂O₇Na₄P₂O₇ Na₄P₂O₇ Mo₂O₈ Tm/ Yb/ Lu/ In/ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mn₃O₄/WO₄Tm/ Yb/ Lu/ In/ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Na₂WO₄ Tm/ Yb/Lu/ In/ Na₂WO₄ Na₂WO₄ Na₂WO₄ Na₂WO₄ Zr₂Mo₂O₈ Tm/ Yb/ Lu/ In/ Zr₂Mo₂O₈Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ NaMnO₄—/ Tm/ Yb/ Lu/ In/ MgO NaMnO₄—/NaMnO₄—/ NaMnO₄—/ NaMnO₄—/ MgO MgO MgO MgO Na₁₀Mn—W₅O₁₇ Tm/ Yb/ Lu/ In/Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇

TABLE 5 NANOWIRES (NW) DOPED WITH SPECIFIC DOPANTS (DOP) Dop NW Y Sc AlCu Li₂O Y/ Sc/ Al/ Cu/ Li₂O Li₂O Li₂O Li₂O Na₂O Y/ Sc/ Al/ Cu/ Na₂O Na₂ONa₂O Na₂O K₂O Y/ Sc/ Al/ Cu/ K₂O K₂O K₂O K₂O Rb₂O Y/ Sc/ Al/ Cu/ Rb₂ORb₂O Rb₂O Rb₂O Cs₂O Y/ Sc/ Al/ Cu/ Cs₂O Cs₂O Cs₂O Cs₂O BeO Y/ Sc/ Al/Cu/ BeO BeO BeO BeO MgO Y/ Sc/ Al/ Cu/ MgO MgO MgO MgO CaO Y/ Sc/ Al/Cu/ CaO CaO CaO CaO SrO Y/ Sc/ Al/ Cu/ SrO SrO SrO SrO BaO Y/ Sc/ Al/Cu/ BaO BaO BaO BaO Sc₂O₃ Y/ Sc/ Al/ Cu/ Sc₂O₃ Sc₂O₃ Sc₂O₃ Sc₂O₃ Y₂O₃ Y/Sc/ Al/ Cu/ Y₂O₃ Y₂O₃ Y₂O₃ Y₂O₃ La₂O₃ Y/ Sc/ Al/ Cu/ La₂O₃ La₂O₃ La₂O₃La₂O₃ CeO₂ Y/ Sc/ Al/ Cu/ CeO₂ CeO₂ CeO₂ CeO₂ Ce₂O₃ Y/ Sc/ Al/ Cu/ Ce₂O₃Ce₂O₃ Ce₂O₃ Ce₂O₃ Pr₂O₃ Y/ Sc/ Al/ Cu/ Pr₂O₃ Pr₂O₃ Pr₂O₃ Pr₂O₃ Nd₂O₃ Y/Sc/ Al/ Cu/ Nd₂O₃ Nd₂O₃ Nd₂O₃ Nd₂O₃ Sm₂O₃ Y/ Sc/ Al/ Cu/ Sm₂O₃ Sm₂O₃Sm₂O₃ Sm₂O₃ Eu₂O₃ Y/ Sc/ Al/ Cu/ Eu₂O₃ Eu₂O₃ Eu₂O₃ Eu₂O₃ Gd₂O₃ Y/ Sc/Al/ Cu/ Gd₂O₃ Gd₂O₃ Gd₂O₃ Gd₂O₃ Tb₂O₃ Y/ Sc/ Al/ Cu/ Tb₂O₃ Tb₂O₃ Tb₂O₃Tb₂O₃ TbO₂ Y/ Sc/ Al/ Cu/ TbO₂ TbO₂ TbO₂ TbO₂ Tb₆O₁₁ Y/ Sc/ Al/ Cu/Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Dy₂O₃ Y/ Sc/ Al/ Cu/ Dy₂O₃ Dy₂O₃ Dy₂O₃ Dy₂O₃Ho₂O₃ Y/ Sc/ Al/ Cu/ Ho₂O₃ Ho₂O₃ Ho₂O₃ Ho₂O₃ Er₂O₃ Y/ Sc/ Al/ Cu/ Er₂O₃Er₂O₃ Er₂O₃ Er₂O₃ Tm₂O₃ Y/ Sc/ Al/ Cu/ Tm₂O₃ Tm₂O₃ Tm₂O₃ Tm₂O₃ Yb₂O₃ Y/Sc/ Al/ Cu/ Yb₂O₃ Yb₂O₃ Yb₂O₃ Yb₂O₃ Lu₂O₃ Y/ Sc/ Al/ Cu/ Lu₂O₃ Lu₂O₃Lu₂O₃ Lu₂O₃ Ac₂O₃ Y/ Sc/ Al/ Cu/ Ac₂O₃ Ac₂O₃ Ac₂O₃ Ac₂O₃ Th₂O₃ Y/ Sc/Al/ Cu/ Th₂O₃ Th₂O₃ Th₂O₃ Th₂O₃ ThO₂ Y/ Sc/ Al/ Cu/ ThO₂ ThO₂ ThO₂ ThO₂Pa₂O₃ Y/ Sc/ Al/ Cu/ Pa₂O₃ Pa₂O₃ Pa₂O₃ Pa₂O₃ PaO₂ Y/ Sc/ Al/ Cu/ PaO₂PaO₂ PaO₂ PaO₂ TiO₂ Y/ Sc/ Al/ Cu/ TiO₂ TiO₂ TiO₂ TiO₂ TiO Y/ Sc/ Al/Cu/ TiO TiO TiO TiO Ti₂O₃ Y/ Sc/ Al/ Cu/ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₃O Y/Sc/ Al/ Cu/ Ti₃O Ti₃O Ti₃O Ti₃O Ti₂O Y/ Sc/ Al/ Cu/ Ti₂O Ti₂O Ti₂O Ti₂OTi₃O₅ Y/ Sc/ Al/ Cu/ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₄O₇ Y/ Sc/ Al/ Cu/ Ti₄O₇Ti₄O₇ Ti₄O₇ Ti₄O₇ ZrO₂ Y/ Sc/ Al/ Cu/ ZrO₂ ZrO₂ ZrO₂ ZrO₂ HfO₂ Y/ Sc/Al/ Cu/ HfO₂ HfO₂ HfO₂ HfO₂ VO Y/ Sc/ Al/ Cu/ VO VO VO VO V₂O₃ Y/ Sc/Al/ Cu/ V₂O₃ V₂O₃ V₂O₃ V₂O₃ VO₂ Y/ Sc/ Al/ Cu/ VO₂ VO₂ VO₂ VO₂ V₂O₅ Y/Sc/ Al/ Cu/ V₂O₅ V₂O₅ V₂O₅ V₂O₅ V₃O₇ Y/ Sc/ Al/ Cu/ V₃O₇ V₃O₇ V₃O₇ V₃O₇V₄O₉ Y/ Sc/ Al/ Cu/ V₄O₉ V₄O₉ V₄O₉ V₄O₉ V₆O₁₃ Y/ Sc/ Al/ Cu/ V₆O₁₃ V₆O₁₃V₆O₁₃ V₆O₁₃ NbO Y/ Sc/ Al/ Cu/ NbO NbO NbO NbO NbO₂ Y/ Sc/ Al/ Cu/ NbO₂NbO₂ NbO₂ NbO₂ Nb₂O₅ Y/ Sc/ Al/ Cu/ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₈O₁₉ Y/Sc/ Al/ Cu/ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₁₆O₃₈ Y/ Sc/ Al/ Cu/ Nb₁₆O₃₈Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₂O₂₉ Y/ Sc/ Al/ Cu/ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉Nb₁₂O₂₉ Nb₄₇O₁₁₆ Y/ Sc/ Al/ Cu/ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆Ta₂O₅ Y/ Sc/ Al/ Cu/ Ta₂O₅ Ta₂O₅ Ta₂O₅ Ta₂O₅ CrO Y/ Sc/ Al/ Cu/ CrO CrOCrO CrO Cr₂O₃ Y/ Sc/ Al/ Cu/ Cr₂O₃ Cr₂O₃ Cr₂O₃ Cr₂O₃ CrO₂ Y/ Sc/ Al/ Cu/CrO₂ CrO₂ CrO₂ CrO₂ CrO₃ Y/ Sc/ Al/ Cu/ CrO₃ CrO₃ CrO₃ CrO₃ Cr₈O₂₁ Y/Sc/ Al/ Cu/ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ MoO₂ Y/ Sc/ Al/ Cu/ MoO₂ MoO₂MoO₂ MoO₂ MoO₃ Y/ Sc/ Al/ Cu/ MoO₃ MoO₃ MoO₃ MoO₃ W₂O₃ Y/ Sc/ Al/ Cu/W₂O₃ W₂O₃ W₂O₃ W₂O₃ WoO₂ Y/ Sc/ Al/ Cu/ WoO₂ WoO₂ WoO₂ WoO₂ MnO Y/ Sc/Al/ Cu/ WoO₃ WoO₃ WoO₃ WoO₃ MnO Y/ Sc/ Al/ Cu/ MnO MnO MnO MnO Mn/Mg/OY/ Sc/ Al/ Cu/ Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn₃O₄ Y/ Sc/ Al/ Cu/Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₂O₃ Y/ Sc/ Al/ Cu/ Mn₂O₃ Mn₂O₃ Mn₂O₃ Mn₂O₃MnO₂ Y/ Sc/ Al/ Cu/ MnO₂ MnO₂ MnO₂ MnO₂ Mn₂O₇ Y/ Sc/ Al/ Cu/ Mn₂O₇ Mn₂O₇Mn₂O₇ Mn₂O₇ ReO₂ Y/ Sc/ Al/ Cu/ ReO₂ ReO₂ ReO₂ ReO₂ ReO₃ Y/ Sc/ Al/ Cu/ReO₃ ReO₃ ReO₃ ReO₃ Re₂O₇ Y/ Sc/ Al/ Cu/ Re₂O₇ Re₂O₇ Re₂O₇ Re₂O₇Mg₃Mn₃—B₂O₁₀ Y/ Sc/ Al/ Cu/ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀Mg₃Mn₃—B₂O₁₀ Mg₃(BO₃)₂ Y/ Sc/ Al/ Cu/ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂Mg₃(BO₃)₂ NaWO₄ Y/ Sc/ Al/ Cu/ NaWO₄ NaWO₄ NaWO₄ NaWO₄ Mg₆MnO₈ Y/ Sc/Al/ Cu/ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ Mn₂O₄ Y/ Sc/ Al/ Cu/ Mn₂O₄ Mn₂O₄Mn₂O₄ Mn₂O₄ (Li,Mg)₆MnO₈ Y/ Sc/ Al/ Cu/ (Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈(Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈ Na₄P₂O₇ Y/ Sc/ Al/ Cu/ Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇Na₄P₂O₇ Mo₂O₈ Y/ Sc/ Al/ Cu/ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mn₃O₄/WO₄ Y/ Sc/Al/ Cu/ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Na₂WO₄ Y/ Sc/ Al/ Cu/Na₂WO₄ Na₂WO₄ Na₂WO₄ Na₂WO₄ Zr₂Mo₂O₈ Y/ Sc/ Al/ Cu/ Zr₂Mo₂O₈ Zr₂Mo₂O₈Zr₂Mo₂O₈ Zr₂Mo₂O₈ NaMnO₄—/ Y/ Sc/ Al/ Cu/ MgO NaMnO₄—/ NaMnO₄—/ NaMnO₄—/NaMnO₄—/ MgO MgO MgO MgO Na₁₀Mn—W₅O₁₇ Y/ Sc/ Al/ Cu/ Na₁₀Mn—W₅O₁₇Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Dop NW Ga Hf Fe Cr Li₂O Ga/ Hf/Fe/ Cr/ Li₂O Li₂O Li₂O Li₂O Na₂O Ga/ Hf/ Fe/ Cr/ Na₂O Na₂O Na₂O Na₂O K₂OGa/ Hf/ Fe/ Cr/ K₂O K₂O K₂O K₂O Rb₂O Ga/ Hf/ Fe/ Cr/ Rb₂O Rb₂O Rb₂O Rb₂OCs₂O Ga/ Hf/ Fe/ Cr/ Cs₂O Cs₂O Cs₂O Cs₂O BeO Ga/ Hf/ Fe/ Cr/ BeO BeO BeOBeO MgO Ga/ Hf/ Fe/ Cr/ MgO MgO MgO MgO CaO Ga/ Hf/ Fe/ Cr/ CaO CaO CaOCaO SrO Ga/ Hf/ Fe/ Cr/ SrO SrO SrO SrO BaO Ga/ Hf/ Fe/ Cr/ BaO BaO BaOBaO Sc₂O₃ Ga/ Hf/ Fe/ Cr/ Sc₂O₃ Sc₂O₃ Sc₂O₃ Sc₂O₃ Y₂O₃ Ga/ Hf/ Fe/ Cr/Y₂O₃ Y₂O₃ Y₂O₃ Y₂O₃ La₂O₃ Ga/ Hf/ Fe/ Cr/ La₂O₃ La₂O₃ La₂O₃ La₂O₃ CeO₂Ga/ Hf/ Fe/ Cr/ CeO₂ CeO₂ CeO₂ CeO₂ Ce₂O₃ Ga/ Hf/ Fe/ Cr/ Ce₂O₃ Ce₂O₃Ce₂O₃ Ce₂O₃ Pr₂O₃ Ga/ Hf/ Fe/ Cr/ Pr₂O₃ Pr₂O₃ Pr₂O₃ Pr₂O₃ Nd₂O₃ Ga/ Hf/Fe/ Cr/ Nd₂O₃ Nd₂O₃ Nd₂O₃ Nd₂O₃ Sm₂O₃ Ga/ Hf/ Fe/ Cr/ Sm₂O₃ Sm₂O₃ Sm₂O₃Sm₂O₃ Eu₂O₃ Ga/ Hf/ Fe/ Cr/ Eu₂O₃ Eu₂O₃ Eu₂O₃ Eu₂O₃ Gd₂O₃ Ga/ Hf/ Fe/Cr/ Gd₂O₃ Gd₂O₃ Gd₂O₃ Gd₂O₃ Tb₂O₃ Ga/ Hf/ Fe/ Cr/ Tb₂O₃ Tb₂O₃ Tb₂O₃Tb₂O₃ TbO₂ Ga/ Hf/ Fe/ Cr/ TbO₂ TbO₂ TbO₂ TbO₂ Tb₆O₁₁ Ga/ Hf/ Fe/ Cr/Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Dy₂O₃ Ga/ Hf/ Fe/ Cr/ Dy₂O₃ Dy₂O₃ Dy₂O₃Dy₂O₃ Ho₂O₃ Ga/ Hf/ Fe/ Cr/ Ho₂O₃ Ho₂O₃ Ho₂O₃ Ho₂O₃ Er₂O₃ Ga/ Hf/ Fe/Cr/ Er₂O₃ Er₂O₃ Er₂O₃ Er₂O₃ Tm₂O₃ Ga/ Hf/ Fe/ Cr/ Tm₂O₃ Tm₂O₃ Tm₂O₃Tm₂O₃ Yb₂O₃ Ga/ Hf/ Fe/ Cr/ Yb₂O₃ Yb₂O₃ Yb₂O₃ Yb₂O₃ Lu₂O₃ Ga/ Hf/ Fe/Cr/ Lu₂O₃ Lu₂O₃ Lu₂O₃ Lu₂O₃ Ac₂O₃ Ga/ Hf/ Fe/ Cr/ Ac₂O₃ Ac₂O₃ Ac₂O₃Ac₂O₃ Th₂O₃ Ga/ Hf/ Fe/ Cr/ Th₂O₃ Th₂O₃ Th₂O₃ Th₂O₃ ThO₂ Ga/ Hf/ Fe/ Cr/ThO₂ ThO₂ ThO₂ ThO₂ Pa₂O₃ Ga/ Hf/ Fe/ Cr/ Pa₂O₃ Pa₂O₃ Pa₂O₃ Pa₂O₃ PaO₂Ga/ Hf/ Fe/ Cr/ PaO₂ PaO₂ PaO₂ PaO₂ TiO₂ Ga/ Hf/ Fe/ Cr/ TiO₂ TiO₂ TiO₂TiO₂ TiO Ga/ Hf/ Fe/ Cr/ TiO TiO TiO TiO Ti₂O₃ Ga/ Hf/ Fe/ Cr/ Ti₂O₃Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₃O Ga/ Hf/ Fe/ Cr/ Ti₃O Ti₃O Ti₃O Ti₃O Ti₂O Ga/ Hf/Fe/ Cr/ Ti₂O Ti₂O Ti₂O Ti₂O Ti₃O₅ Ga/ Hf/ Fe/ Cr/ Ti₃O₅ Ti₃O₅ Ti₃O₅Ti₃O₅ Ti₄O₇ Ga/ Hf/ Fe/ Cr/ Ti₄O₇ Ti₄O₇ Ti₄O₇ Ti₄O₇ ZrO₂ Ga/ Hf/ Fe/ Cr/ZrO₂ ZrO₂ ZrO₂ ZrO₂ HfO₂ Ga/ Hf/ Fe/ Cr/ HfO₂ HfO₂ HfO₂ HfO₂ VO Ga/ Hf/Fe/ Cr/ VO VO VO VO V₂O₃ Ga/ Hf/ Fe/ Cr/ V₂O₃ V₂O₃ V₂O₃ V₂O₃ VO₂ Ga/ Hf/Fe/ Cr/ VO₂ VO₂ VO₂ VO₂ V₂O₅ Ga/ Hf/ Fe/ Cr/ V₂O₅ V₂O₅ V₂O₅ V₂O₅ V₃O₇Ga/ Hf/ Fe/ Cr/ V₃O₇ V₃O₇ V₃O₇ V₃O₇ V₄O₉ Ga/ Hf/ Fe/ Cr/ V₄O₉ V₄O₉ V₄O₉V₄O₉ V₆O₁₃ Ga/ Hf/ Fe/ Cr/ V₆O₁₃ V₆O₁₃ V₆O₁₃ V₆O₁₃ NbO Ga/ Hf/ Fe/ Cr/NbO NbO NbO NbO NbO₂ Ga/ Hf/ Fe/ Cr/ NbO₂ NbO₂ NbO₂ NbO₂ Nb₂O₅ Ga/ Hf/Fe/ Cr/ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₈O₁₉ Ga/ Hf/ Fe/ Cr/ Nb₈O₁₉ Nb₈O₁₉Nb₈O₁₉ Nb₈O₁₉ Nb₁₆O₃₈ Ga/ Hf/ Fe/ Cr/ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈Nb₁₂O₂₉ Ga/ Hf/ Fe/ Cr/ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₄₇O₁₁₆ Ga/ Hf/Fe/ Cr/ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Ta₂O₅ Ga/ Hf/ Fe/ Cr/ Ta₂O₅Ta₂O₅ Ta₂O₅ Ta₂O₅ CrO Ga/ Hf/ Fe/ Cr/ CrO CrO CrO CrO Cr₂O₃ Ga/ Hf/ Fe/Cr/ Cr₂O₃ Cr₂O₃ Cr₂O₃ Cr₂O₃ CrO₂ Ga/ Hf/ Fe/ Cr/ CrO₂ CrO₂ CrO₂ CrO₂CrO₃ Ga/ Hf/ Fe/ Cr/ CrO₃ CrO₃ CrO₃ CrO₃ Cr₈O₂₁ Ga/ Hf/ Fe/ Cr/ Cr₈O₂₁Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ MoO₂ Ga/ Hf/ Fe/ Cr/ MoO₂ MoO₂ MoO₂ MoO₂ MoO₃ Ga/Hf/ Fe/ Cr/ MoO₃ MoO₃ MoO₃ MoO₃ W₂O₃ Ga/ Hf/ Fe/ Cr/ W₂O₃ W₂O₃ W₂O₃ W₂O₃WoO₂ Ga/ Hf/ Fe/ Cr/ WoO₂ WoO₂ WoO₂ WoO₂ MnO Ga/ Hf/ Fe/ Cr/ WoO₃ WoO₃WoO₃ WoO₃ MnO Ga/ Hf/ Fe/ Cr/ MnO MnO MnO MnO Mn/Mg/O Ga/ Hf/ Fe/ Cr/Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn₃O₄ Ga/ Hf/ Fe/ Cr/ Mn₃O₄ Mn₃O₄ Mn₃O₄Mn₃O₄ Mn₂O₃ Ga/ Hf/ Fe/ Cr/ Mn₂O₃ Mn₂O₃ Mn₂O₃ Mn₂O₃ MnO₂ Ga/ Hf/ Fe/ Cr/MnO₂ MnO₂ MnO₂ MnO₂ Mn₂O₇ Ga/ Hf/ Fe/ Cr/ Mn₂O₇ Mn₂O₇ Mn₂O₇ Mn₂O₇ ReO₂Ga/ Hf/ Fe/ Cr/ ReO₂ ReO₂ ReO₂ ReO₂ ReO₃ Ga/ Hf/ Fe/ Cr/ ReO₃ ReO₃ ReO₃ReO₃ Re₂O₇ Ga/ Hf/ Fe/ Cr/ Re₂O₇ Re₂O₇ Re₂O₇ Re₂O₇ Mg₃Mn₃—B₂O₁₀ Ga/ Hf/Fe/ Cr/ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃(BO₃)₂Ga/ Hf/ Fe/ Cr/ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂ NaWO₄ Ga/ Hf/Fe/ Cr/ NaWO₄ NaWO₄ NaWO₄ NaWO₄ Mg₆MnO₈ Ga/ Hf/ Fe/ Cr/ Mg₆MnO₈ Mg₆MnO₈Mg₆MnO₈ Mg₆MnO₈ Mn₂O₄ Ga/ Hf/ Fe/ Cr/ Mn₂O₄ Mn₂O₄ Mn₂O₄ Mn₂O₄(Li,Mg)₆MnO₈ Ga/ Hf/ Fe/ Cr/ (Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈ (Li,Mg)₆MnO₈(Li,Mg)₆MnO₈ Na₄P₂O₇ Ga/ Hf/ Fe/ Cr/ Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇Mo₂O₈ Ga/ Hf/ Fe/ Cr/ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mn₃O₄/WO₄ Ga/ Hf/ Fe/ Cr/Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Na₂WO₄ Ga/ Hf/ Fe/ Cr/ Na₂WO₄Na₂WO₄ Na₂WO₄ Na₂WO₄ Zr₂Mo₂O₈ Ga/ Hf/ Fe/ Cr/ Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈Zr₂Mo₂O₈ NaMnO₄—/ Ga/ Hf/ Fe/ Cr/ MgO NaMnO₄—/ NaMnO₄—/ NaMnO₄—/NaMnO₄—/ MgO MgO MgO MgO Na₁₀Mn—W₅O₁₇ Ga/ Hf/ Fe/ Cr/ Na₁₀Mn—W₅O₁₇Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇

TABLE 6 NANOWIRES (NW) DOPED WITH SPECIFIC DOPANTS (DOP) Dop NW Ru Sr ZrTa Li₂O Ru/ Sr/ Zr/ Ta/ Li₂O Li₂O Li₂O Li₂O Na₂O Ru/ Sr/ Zr/ Ta/ Na₂ONa₂O Na₂O Na₂O K₂O Ru/ Sr/ Zr/ Ta/ K₂O K₂O K₂O K₂O Rb₂O Ru/ Sr/ Zr/ Ta/Rb₂O Rb₂O Rb₂O Rb₂O Cs₂O Ru/ Sr/ Zr/ Ta/ Cs₂O Cs₂O Cs₂O Cs₂O BeO Ru/ Sr/Zr/ Ta/ BeO BeO BeO BeO MgO Ru/ Sr/ Zr/ Ta/ MgO MgO MgO MgO CaO Ru/ Sr/Zr/ Ta/ CaO CaO CaO CaO SrO Ru/ Sr/ Zr/ Ta/ SrO SrO SrO SrO BaO Ru/ Sr/Zr/ Ta/ BaO BaO BaO BaO Sc₂O₃ Ru/ Sr/ Zr/ Ta/ Sc₂O₃ Sc₂O₃ Sc₂O₃ Sc₂O₃Y₂O₃ Ru/ Sr/ Zr/ Ta/ Y₂O₃ Y₂O₃ Y₂O₃ Y₂O₃ La₂O₃ Ru/ Sr/ Zr/ Ta/ La₂O₃La₂O₃ La₂O₃ La₂O₃ CeO₂ Ru/ Sr/ Zr/ Ta/ CeO₂ CeO₂ CeO₂ CeO₂ Ce₂O₃ Ru/ Sr/Zr/ Ta/ Ce₂O₃ Ce₂O₃ Ce₂O₃ Ce₂O₃ Pr₂O₃ Ru/ Sr/ Zr/ Ta/ Pr₂O₃ Pr₂O₃ Pr₂O₃Pr₂O₃ Nd₂O₃ Ru/ Sr/ Zr/ Ta/ Nd₂O₃ Nd₂O₃ Nd₂O₃ Nd₂O₃ Sm₂O₃ Ru/ Sr/ Zr/Ta/ Sm₂O₃ Sm₂O₃ Sm₂O₃ Sm₂O₃ Eu₂O₃ Ru/ Sr/ Zr/ Ta/ Eu₂O₃ Eu₂O₃ Eu₂O₃Eu₂O₃ Gd₂O₃ Ru/ Sr/ Zr/ Ta/ Gd₂O₃ Gd₂O₃ Gd₂O₃ Gd₂O₃ Tb₂O₃ Ru/ Sr/ Zr/Ta/ Tb₂O₃ Tb₂O₃ Tb₂O₃ Tb₂O₃ TbO₂ Ru/ Sr/ Zr/ Ta/ TbO₂ TbO₂ TbO₂ TbO₂Tb₆O₁₁ Ru/ Sr/ Zr/ Ta/ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Dy₂O₃ Ru/ Sr/ Zr/ Ta/Dy₂O₃ Dy₂O₃ Dy₂O₃ Dy₂O₃ Ho₂O₃ Ru/ Sr/ Zr/ Ta/ Ho₂O₃ Ho₂O₃ Ho₂O₃ Ho₂O₃Er₂O₃ Ru/ Sr/ Zr/ Ta/ Er₂O₃ Er₂O₃ Er₂O₃ Er₂O₃ Tm₂O₃ Ru/ Sr/ Zr/ Ta/Tm₂O₃ Tm₂O₃ Tm₂O₃ Tm₂O₃ Yb₂O₃ Ru/ Sr/ Zr/ Ta/ Yb₂O₃ Yb₂O₃ Yb₂O₃ Yb₂O₃Lu₂O₃ Ru/ Sr/ Zr/ Ta/ Lu₂O₃ Lu₂O₃ Lu₂O₃ Lu₂O₃ Ac₂O₃ Ru/ Sr/ Zr/ Ta/Ac₂O₃ Ac₂O₃ Ac₂O₃ Ac₂O₃ Th₂O₃ Ru/ Sr/ Zr/ Ta/ Th₂O₃ Th₂O₃ Th₂O₃ Th₂O₃ThO₂ Ru/ Sr/ Zr/ Ta/ ThO₂ ThO₂ ThO₂ ThO₂ Pa₂O₃ Ru/ Sr/ Zr/ Ta/ Pa₂O₃Pa₂O₃ Pa₂O₃ Pa₂O₃ PaO₂ Ru/ Sr/ Zr/ Ta/ PaO₂ PaO₂ PaO₂ PaO₂ TiO₂ Ru/ Sr/Zr/ Ta/ TiO₂ TiO₂ TiO₂ TiO₂ TiO Ru/ Sr/ Zr/ Ta/ TiO TiO TiO TiO Ti₂O₃Ru/ Sr/ Zr/ Ta/ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₃O Ru/ Sr/ Zr/ Ta/ Ti₃O Ti₃OTi₃O Ti₃O Ti₂O Ru/ Sr/ Zr/ Ta/ Ti₂O Ti₂O Ti₂O Ti₂O Ti₃O₅ Ru/ Sr/ Zr/ Ta/Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₄O₇ Ru/ Sr/ Zr/ Ta/ Ti₄O₇ Ti₄O₇ Ti₄O₇ Ti₄O₇ZrO₂ Ru/ Sr/ Zr/ Ta/ ZrO₂ ZrO₂ ZrO₂ ZrO₂ HfO₂ Ru/ Sr/ Zr/ Ta/ HfO₂ HfO₂HfO₂ HfO₂ VO Ru/ Sr/ Zr/ Ta/ VO VO VO VO V₂O₃ Ru/ Sr/ Zr/ Ta/ V₂O₃ V₂O₃V₂O₃ V₂O₃ VO₂ Ru/ Sr/ Zr/ Ta/ VO₂ VO₂ VO₂ VO₂ V₂O₅ Ru/ Sr/ Zr/ Ta/ V₂O₅V₂O₅ V₂O₅ V₂O₅ V₃O₇ Ru/ Sr/ Zr/ Ta/ V₃O₇ V₃O₇ V₃O₇ V₃O₇ V₄O₉ Ru/ Sr/ Zr/Ta/ V₄O₉ V₄O₉ V₄O₉ V₄O₉ V₆O₁₃ Ru/ Sr/ Zr/ Ta/ V₆O₁₃ V₆O₁₃ V₆O₁₃ V₆O₁₃NbO Ru/ Sr/ Zr/ Ta/ NbO NbO NbO NbO NbO₂ Ru/ Sr/ Zr/ Ta/ NbO₂ NbO₂ NbO₂NbO₂ Nb₂O₅ Ru/ Sr/ Zr/ Ta/ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₈O₁₉ Ru/ Sr/ Zr/Ta/ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₁₆O₃₈ Ru/ Sr/ Zr/ Ta/ Nb₁₆O₃₈ Nb₁₆O₃₈Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₂O₂₉ Ru/ Sr/ Zr/ Ta/ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉Nb₄₇O₁₁₆ Ru/ Sr/ Zr/ Ta/ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Ta₂O₅ Ru/Sr/ Zr/ Ta/ Ta₂O₅ Ta₂O₅ Ta₂O₅ Ta₂O₅ CrO Ru/ Sr/ Zr/ Ta/ CrO CrO CrO CrOCr₂O₃ Ru/ Sr/ Zr/ Ta/ Cr₂O₃ Cr₂O₃ Cr₂O₃ Cr₂O₃ CrO₂ Ru/ Sr/ Zr/ Ta/ CrO₂CrO₂ CrO₂ CrO₂ CrO₃ Ru/ Sr/ Zr/ Ta/ CrO₃ CrO₃ CrO₃ CrO₃ Cr₈O₂₁ Ru/ Sr/Zr/ Ta/ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ MoO₂ Ru/ Sr/ Zr/ Ta/ MoO₂ MoO₂ MoO₂MoO₂ MoO₃ Ru/ Sr/ Zr/ Ta/ MoO₃ MoO₃ MoO₃ MoO₃ W₂O₃ Ru/ Sr/ Zr/ Ta/ W₂O₃W₂O₃ W₂O₃ W₂O₃ WoO₂ Ru/ Sr/ Zr/ Ta/ WoO₂ WoO₂ WoO₂ WoO₂ WoO₃ Ru/ Sr/ Zr/Ta/ WoO₃ WoO₃ WoO₃ WoO₃ MnO Ru/ Sr/ Zr/ Ta/ MnO MnO MnO MnO Mn/Mg/O Ru/Sr/ Zr/ Ta/ Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn₃O₄ Ru/ Sr/ Zr/ Ta/ Mn₃O₄Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₂O₃ Ru/ Sr/ Zr/ Ta/ Mn₂O₃ Mn₂O₃ Mn₂O₃ Mn₂O₃ MnO₂ Ru/Sr/ Zr/ Ta/ MnO₂ MnO₂ MnO₂ MnO₂ Mn₂O₇ Ru/ Sr/ Zr/ Ta/ Mn₂O₇ Mn₂O₇ Mn₂O₇Mn₂O₇ ReO₂ Ru/ Sr/ Zr/ Ta/ ReO₂ ReO₂ ReO₂ ReO₂ ReO₃ Ru/ Sr/ Zr/ Ta/ ReO₃ReO₃ ReO₃ ReO₃ Re₂O₇ Ru/ Sr/ Zr/ Ta/ Re₂O₇ Re₂O₇ Re₂O₇ Re₂O₇Mg₃Mn₃—B₂O₁₀ Ru/ Sr/ Zr/ Ta/ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀Mg₃Mn₃—B₂O₁₀ Mg₃(BO₃)₂ Ru/ Sr/ Zr/ Ta/ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂Mg₃(BO₃)₂ NaWO₄ Ru/ Sr/ Zr/ Ta/ NaWO₄ NaWO₄ NaWO₄ NaWO₄ Mg₆MnO₈ Ru/ Sr/Zr/ Ta/ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ Mn₂O₄ Ru/ Sr/ Zr/ Ta/ Mn₂O₄Mn₂O₄ Mn₂O₄ Mn₂O₄ (Li,Mg)₆—MnO₈ Ru/ Sr/ Zr/ Ta/ (Li,Mg)₆—MnO₈(Li,Mg)₆—MnO₈ (Li,Mg)₆—MnO₈ (Li,Mg)₆—MnO₈ Na₄P₂O₇ Ru/ Sr/ Zr/ Ta/Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇ Mo₂O₈ Ru/ Sr/ Zr/ Ta/ Mo₂O₈ Mo₂O₈ Mo₂O₈Mo₂O₈ Mn₃O₄/WO₄ Ru/ Sr/ Zr/ Ta/ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄Na₂WO₄ Ru/ Sr/ Zr/ Ta/ Na₂WO₄ Na₂WO₄ Na₂WO₄ Na₂WO₄ Zr₂Mo₂O₈ Ru/ Sr/ Zr/Ta/ Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ NaMnO₄—/ Ru/ Sr/ Zr/ Ta/ MgONaMnO₄—/ NaMnO₄—/ NaMnO₄—/ NaMnO₄—/ MgO MgO MgO MgO Na₁₀Mn—W₅O₁₇ Ru/ Sr/Zr/ Ta/ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Dop NW Rh AuMo Ni Li₂O Rh/ Au/ Mo/ Ni/ Li₂O Li₂O Li₂O Li₂O Na₂O Rh/ Au/ Mo/ Ni/ Na₂ONa₂O Na₂O Na₂O K₂O Rh/ Au/ Mo/ Ni/ K₂O K₂O K₂O K₂O Rb₂O Rh/ Au/ Mo/ Ni/Rb₂O Rb₂O Rb₂O Rb₂O Cs₂O Rh/ Au/ Mo/ Ni/ Cs₂O Cs₂O Cs₂O Cs₂O BeO Rh/ Au/Mo/ Ni/ BeO BeO BeO BeO MgO Rh/ Au/ Mo/ Ni/ MgO MgO MgO MgO CaO Rh/ Au/Mo/ Ni/ CaO CaO CaO CaO SrO Rh/ Au/ Mo/ Ni/ SrO SrO SrO SrO BaO Rh/ Au/Mo/ Ni/ BaO BaO BaO BaO Sc₂O₃ Rh/ Au/ Mo/ Ni/ Sc₂O₃ Sc₂O₃ Sc₂O₃ Sc₂O₃Y₂O₃ Rh/ Au/ Mo/ Ni/ Y₂O₃ Y₂O₃ Y₂O₃ Y₂O₃ La₂O₃ Rh/ Au/ Mo/ Ni/ La₂O₃La₂O₃ La₂O₃ La₂O₃ CeO₂ Rh/ Au/ Mo/ Ni/ CeO₂ CeO₂ CeO₂ CeO₂ Ce₂O₃ Rh/ Au/Mo/ Ni/ Ce₂O₃ Ce₂O₃ Ce₂O₃ Ce₂O₃ Pr₂O₃ Rh/ Au/ Mo/ Ni/ Pr₂O₃ Pr₂O₃ Pr₂O₃Pr₂O₃ Nd₂O₃ Rh/ Au/ Mo/ Ni/ Nd₂O₃ Nd₂O₃ Nd₂O₃ Nd₂O₃ Sm₂O₃ Rh/ Au/ Mo/Ni/ Sm₂O₃ Sm₂O₃ Sm₂O₃ Sm₂O₃ Eu₂O₃ Rh/ Au/ Mo/ Ni/ Eu₂O₃ Eu₂O₃ Eu₂O₃Eu₂O₃ Gd₂O₃ Rh/ Au/ Mo/ Ni/ Gd₂O₃ Gd₂O₃ Gd₂O₃ Gd₂O₃ Tb₂O₃ Rh/ Au/ Mo/Ni/ Tb₂O₃ Tb₂O₃ Tb₂O₃ Tb₂O₃ TbO₂ Rh/ Au/ Mo/ Ni/ TbO₂ TbO₂ TbO₂ TbO₂Tb₆O₁₁ Rh/ Au/ Mo/ Ni/ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Dy₂O₃ Rh/ Au/ Mo/ Ni/Dy₂O₃ Dy₂O₃ Dy₂O₃ Dy₂O₃ Ho₂O₃ Rh/ Au/ Mo/ Ni/ Ho₂O₃ Ho₂O₃ Ho₂O₃ Ho₂O₃Er₂O₃ Rh/ Au/ Mo/ Ni/ Er₂O₃ Er₂O₃ Er₂O₃ Er₂O₃ Tm₂O₃ Rh/ Au/ Mo/ Ni/Tm₂O₃ Tm₂O₃ Tm₂O₃ Tm₂O₃ Yb₂O₃ Rh/ Au/ Mo/ Ni/ Yb₂O₃ Yb₂O₃ Yb₂O₃ Yb₂O₃Lu₂O₃ Rh/ Au/ Mo/ Ni/ Lu₂O₃ Lu₂O₃ Lu₂O₃ Lu₂O₃ Ac₂O₃ Rh/ Au/ Mo/ Ni/Ac₂O₃ Ac₂O₃ Ac₂O₃ Ac₂O₃ Th₂O₃ Rh/ Au/ Mo/ Ni/ Th₂O₃ Th₂O₃ Th₂O₃ Th₂O₃ThO₂ Rh/ Au/ Mo/ Ni/ ThO₂ ThO₂ ThO₂ ThO₂ Pa₂O₃ Rh/ Au/ Mo/ Ni/ Pa₂O₃Pa₂O₃ Pa₂O₃ Pa₂O₃ PaO₂ Rh/ Au/ Mo/ Ni/ PaO₂ PaO₂ PaO₂ PaO₂ TiO₂ Rh/ Au/Mo/ Ni/ TiO₂ TiO₂ TiO₂ TiO₂ TiO Rh/ Au/ Mo/ Ni/ TiO TiO TiO TiO Ti₂O₃Rh/ Au/ Mo/ Ni/ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₃O Rh/ Au/ Mo/ Ni/ Ti₃O Ti₃OTi₃O Ti₃O Ti₂O Rh/ Au/ Mo/ Ni/ Ti₂O Ti₂O Ti₂O Ti₂O Ti₃O₅ Rh/ Au/ Mo/ Ni/Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₃O₅ Ti₄O₇ Rh/ Au/ Mo/ Ni/ Ti₄O₇ Ti₄O₇ Ti₄O₇ Ti₄O₇ZrO₂ Rh/ Au/ Mo/ Ni/ ZrO₂ ZrO₂ ZrO₂ ZrO₂ HfO₂ Rh/ Au/ Mo/ Ni/ HfO₂ HfO₂HfO₂ HfO₂ VO Rh/ Au/ Mo/ Ni/ VO VO VO VO V₂O₃ Rh/ Au/ Mo/ Ni/ V₂O₃ V₂O₃V₂O₃ V₂O₃ VO₂ Rh/ Au/ Mo/ Ni/ VO₂ VO₂ VO₂ VO₂ V₂O₅ Rh/ Au/ Mo/ Ni/ V₂O₅V₂O₅ V₂O₅ V₂O₅ V₃O₇ Rh/ Au/ Mo/ Ni/ V₃O₇ V₃O₇ V₃O₇ V₃O₇ V₄O₉ Rh/ Au/ Mo/Ni/ V₄O₉ V₄O₉ V₄O₉ V₄O₉ V₆O₁₃ Rh/ Au/ Mo/ Ni/ V₆O₁₃ V₆O₁₃ V₆O₁₃ V₆O₁₃NbO Rh/ Au/ Mo/ Ni/ NbO NbO NbO NbO NbO₂ Rh/ Au/ Mo/ Ni/ NbO₂ NbO₂ NbO₂NbO₂ Nb₂O₅ Rh/ Au/ Mo/ Ni/ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₈O₁₉ Rh/ Au/ Mo/Ni/ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₁₆O₃₈ Rh/ Au/ Mo/ Ni/ Nb₁₆O₃₈ Nb₁₆O₃₈Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₂O₂₉ Rh/ Au/ Mo/ Ni/ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉Nb₄₇O₁₁₆ Rh/ Au/ Mo/ Ni/ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Ta₂O₅ Rh/Au/ Mo/ Ni/ Ta₂O₅ Ta₂O₅ Ta₂O₅ Ta₂O₅ CrO Rh/ Au/ Mo/ Ni/ CrO CrO CrO CrOCr₂O₃ Rh/ Au/ Mo/ Ni/ Cr₂O₃ Cr₂O₃ Cr₂O₃ Cr₂O₃ CrO₂ Rh/ Au/ Mo/ Ni/ CrO₂CrO₂ CrO₂ CrO₂ CrO₃ Rh/ Au/ Mo/ Ni/ CrO₃ CrO₃ CrO₃ CrO₃ Cr₈O₂₁ Rh/ Au/Mo/ Ni/ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ MoO₂ Rh/ Au/ Mo/ Ni/ MoO₂ MoO₂ MoO₂MoO₂ MoO₃ Rh/ Au/ Mo/ Ni/ MoO₃ MoO₃ MoO₃ MoO₃ W₂O₃ Rh/ Au/ Mo/ Ni/ W₂O₃W₂O₃ W₂O₃ W₂O₃ WoO₂ Rh/ Au/ Mo/ Ni/ WoO₂ WoO₂ WoO₂ WoO₂ WoO₃ Rh/ Au/ Mo/Ni/ WoO₃ WoO₃ WoO₃ WoO₃ MnO Rh/ Au/ Mo/ Ni/ MnO MnO MnO MnO Mn/Mg/O Rh/Au/ Mo/ Ni/ Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn₃O₄ Rh/ Au/ Mo/ Ni/ Mn₃O₄Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₂O₃ Rh/ Au/ Mo/ Ni/ Mn₂O₃ Mn₂O₃ Mn₂O₃ Mn₂O₃ MnO₂ Rh/Au/ Mo/ Ni/ MnO₂ MnO₂ MnO₂ MnO₂ Mn₂O₇ Rh/ Au/ Mo/ Ni/ Mn₂O₇ Mn₂O₇ Mn₂O₇Mn₂O₇ ReO₂ Rh/ Au/ Mo/ Ni/ ReO₂ ReO₂ ReO₂ ReO₂ ReO₃ Rh/ Au/ Mo/ Ni/ ReO₃ReO₃ ReO₃ ReO₃ Re₂O₇ Rh/ Au/ Mo/ Ni/ Re₂O₇ Re₂O₇ Re₂O₇ Re₂O₇Mg₃Mn₃—B₂O₁₀ Rh/ Au/ Mo/ Ni/ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀Mg₃Mn₃—B₂O₁₀ Mg₃(BO₃)₂ Rh/ Au/ Mo/ Ni/ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂Mg₃(BO₃)₂ NaWO₄ Rh/ Au/ Mo/ Ni/ NaWO₄ NaWO₄ NaWO₄ NaWO₄ Mg₆MnO₈ Rh/ Au/Mo/ Ni/ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ Mn₂O₄ Rh/ Au/ Mo/ Ni/ Mn₂O₄Mn₂O₄ Mn₂O₄ Mn₂O₄ (Li,Mg)₆—MnO₈ Rh/ Au/ Mo/ Ni/ (Li,Mg)₆—MnO₈(Li,Mg)₆—MnO₈ (Li,Mg)₆—MnO₈ (Li,Mg)₆—MnO₈ Na₄P₂O₇ Rh/ Au/ Mo/ Ni/Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇ Mo₂O₈ Rh/ Au/ Mo/ Ni/ Mo₂O₈ Mo₂O₈ Mo₂O₈Mo₂O₈ Mn₃O₄/WO₄ Rh/ Au/ Mo/ Ni/ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄Na₂WO₄ Rh/ Au/ Mo/ Ni/ Na₂WO₄ Na₂WO₄ Na₂WO₄ Na₂WO₄ Zr₂Mo₂O₈ Rh/ Au/ Mo/Ni/ Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈ NaMnO₄—/ Rh/ Au/ Mo/ Ni/ MgONaMnO₄—/ NaMnO₄—/ NaMnO₄—/ NaMnO₄—/ MgO MgO MgO MgO Na₁₀Mn—W₅O₁₇ Rh/ Au/Mo/ Ni/ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇

TABLE 7 NANOWIRES (NW) DOPED WITH SPECIFIC DOPANTS (DOP) Dop NW Co Sb WV Li₂O Co/ Sb/ W/ V/ Li₂O Li₂O Li₂O Li₂O Na₂O Co/ Sb/ W/ V/ Na₂O Na₂ONa₂O Na₂O K₂O Co/ Sb/ W/ V/ K₂O K₂O K₂O K₂O Rb₂O Co/ Sb/ W/ V/ Rb₂O Rb₂ORb₂O Rb₂O Cs₂O Co/ Sb/ W/ V/ Cs₂O Cs₂O Cs₂O Cs₂O BeO Co/ Sb/ W/ V/ BeOBeO BeO BeO MgO Co/ Sb/ W/ V/ MgO MgO MgO MgO CaO Co/ Sb/ W/ V/ CaO CaOCaO CaO SrO Co/ Sb/ W/ V/ SrO SrO SrO SrO BaO Co/ Sb/ W/ V/ BaO BaO BaOBaO Sc₂O₃ Co/ Sb/ W/ V/ Sc₂O₃ Sc₂O₃ Sc₂O₃ Sc₂O₃ Y₂O₃ Co/ Sb/ W/ V/ Y₂O₃Y₂O₃ Y₂O₃ Y₂O₃ La₂O₃ Co/ Sb/ W/ V/ La₂O₃ La₂O₃ La₂O₃ La₂O₃ CeO₂ Co/ Sb/W/ V/ CeO₂ CeO₂ CeO₂ CeO₂ Ce₂O₃ Co/ Sb/ W/ V/ Ce₂O₃ Ce₂O₃ Ce₂O₃ Ce₂O₃Pr₂O₃ Co/ Sb/ W/ V/ Pr₂O₃ Pr₂O₃ Pr₂O₃ Pr₂O₃ Nd₂O₃ Co/ Sb/ W/ V/ Nd₂O₃Nd₂O₃ Nd₂O₃ Nd₂O₃ Sm₂O₃ Co/ Sb/ W/ V/ Sm₂O₃ Sm₂O₃ Sm₂O₃ Sm₂O₃ Eu₂O₃ Co/Sb/ W/ V/ Eu₂O₃ Eu₂O₃ Eu₂O₃ Eu₂O₃ Gd₂O₃ Co/ Sb/ W/ V/ Gd₂O₃ Gd₂O₃ Gd₂O₃Gd₂O₃ Tb₂O₃ Co/ Sb/ W/ V/ Tb₂O₃ Tb₂O₃ Tb₂O₃ Tb₂O₃ TbO₂ Co/ Sb/ W/ V/TbO₂ TbO₂ TbO₂ TbO₂ Tb₆O₁₁ Co/ Sb/ W/ V/ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁Dy₂O₃ Co/ Sb/ W/ V/ Dy₂O₃ Dy₂O₃ Dy₂O₃ Dy₂O₃ Ho₂O₃ Co/ Sb/ W/ V/ Ho₂O₃Ho₂O₃ Ho₂O₃ Ho₂O₃ Er₂O₃ Co/ Sb/ W/ V/ Er₂O₃ Er₂O₃ Er₂O₃ Er₂O₃ Tm₂O₃ Co/Sb/ W/ V/ Tm₂O₃ Tm₂O₃ Tm₂O₃ Tm₂O₃ Yb₂O₃ Co/ Sb/ W/ V/ Yb₂O₃ Yb₂O₃ Yb₂O₃Yb₂O₃ Lu₂O₃ Co/ Sb/ W/ V/ Lu₂O₃ Lu₂O₃ Lu₂O₃ Lu₂O₃ Ac₂O₃ Co/ Sb/ W/ V/Ac₂O₃ Ac₂O₃ Ac₂O₃ Ac₂O₃ Th₂O₃ Co/ Sb/ W/ V/ Th₂O₃ Th₂O₃ Th₂O₃ Th₂O₃ ThO₂Co/ Sb/ W/ V/ ThO₂ ThO₂ ThO₂ ThO₂ Pa₂O₃ Co/ Sb/ W/ V/ Pa₂O₃ Pa₂O₃ Pa₂O₃Pa₂O₃ PaO₂ Co/ Sb/ W/ V/ PaO₂ PaO₂ PaO₂ PaO₂ TiO₂ Co/ Sb/ W/ V/ TiO₂TiO₂ TiO₂ TiO₂ TiO Co/ Sb/ W/ V/ TiO TiO TiO TiO Ti₂O₃ Co/ Sb/ W/ V/Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₃O Co/ Sb/ W/ V/ Ti₃O Ti₃O Ti₃O Ti₃O Ti₂O Co/Sb/ W/ V/ Ti₂O Ti₂O Ti₂O Ti₂O Ti₃O₅ Co/ Sb/ W/ V/ Ti₃O₅ Ti₃O₅ Ti₃O₅Ti₃O₅ Ti₄O₇ Co/ Sb/ W/ V/ Ti₄O₇ Ti₄O₇ Ti₄O₇ Ti₄O₇ ZrO₂ Co/ Sb/ W/ V/ZrO₂ ZrO₂ ZrO₂ ZrO₂ HfO₂ Co/ Sb/ W/ V/ HfO₂ HfO₂ HfO₂ HfO₂ VO Co/ Sb/ W/V/ VO VO VO VO V₂O₃ Co/ Sb/ W/ V/ V₂O₃ V₂O₃ V₂O₃ V₂O₃ VO₂ Co/ Sb/ W/ V/VO₂ VO₂ VO₂ VO₂ V₂O₅ Co/ Sb/ W/ V/ V₂O₅ V₂O₅ V₂O₅ V₂O₅ V₃O₇ Co/ Sb/ W/V/ V₃O₇ V₃O₇ V₃O₇ V₃O₇ V₄O₉ Co/ Sb/ W/ V/ V₄O₉ V₄O₉ V₄O₉ V₄O₉ V₆O₁₃ Co/Sb/ W/ V/ V₆O₁₃ V₆O₁₃ V₆O₁₃ V₆O₁₃ NbO Co/ Sb/ W/ V/ NbO NbO NbO NbO NbO₂Co/ Sb/ W/ V/ NbO₂ NbO₂ NbO₂ NbO₂ Nb₂O₅ Co/ Sb/ W/ V/ Nb₂O₅ Nb₂O₅ Nb₂O₅Nb₂O₅ Nb₈O₁₉ Co/ Sb/ W/ V/ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₈O₁₉ Nb₁₆O₃₈ Co/ Sb/W/ V/ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₂O₂₉ Co/ Sb/ W/ V/ Nb₁₂O₂₉Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₄₇O₁₁₆ Co/ Sb/ W/ V/ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Ta₂O₅ Co/ Sb/ W/ V/ Ta₂O₅ Ta₂O₅ Ta₂O₅ Ta₂O₅ CrO Co/Sb/ W/ V/ CrO CrO CrO CrO Cr₂O₃ Co/ Sb/ W/ V/ Cr₂O₃ Cr₂O₃ Cr₂O₃ Cr₂O₃CrO₂ Co/ Sb/ W/ V/ CrO₂ CrO₂ CrO₂ CrO₂ CrO₃ Co/ Sb/ W/ V/ CrO₃ CrO₃ CrO₃CrO₃ Cr₈O₂₁ Co/ Sb/ W/ V/ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ MoO₂ Co/ Sb/ W/ V/MoO₂ MoO₂ MoO₂ MoO₂ MoO₃ Co/ Sb/ W/ V/ MoO₃ MoO₃ MoO₃ MoO₃ W₂O₃ Co/ Sb/W/ V/ W₂O₃ W₂O₃ W₂O₃ W₂O₃ WoO₂ Co/ Sb/ W/ V/ WoO₂ WoO₂ WoO₂ WoO₂ WoO₃Co/ Sb/ W/ V/ WoO₃ WoO₃ WoO₃ WoO₃ MnO Co/ Sb/ W/ V/ MnO MnO MnO MnOMn/Mg/O Co/ Sb/ W/ V/ Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn₃O₄ Co/ Sb/ W/V/ Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₃O₄ Mn₂O₃ Co/ Sb/ W/ V/ Mn₂O₃ Mn₂O₃ Mn₂O₃ Mn₂O₃MnO₂ Co/ Sb/ W/ V/ MnO₂ MnO₂ MnO₂ MnO₂ Mn₂O₇ Co/ Sb/ W/ V/ Mn₂O₇ Mn₂O₇Mn₂O₇ Mn₂O₇ ReO₂ Co/ Sb/ W/ V/ ReO₂ ReO₂ ReO₂ ReO₂ ReO₃ Co/ Sb/ W/ V/ReO₃ ReO₃ ReO₃ ReO₃ Re₂O₇ Co/ Sb/ W/ V/ Re₂O₇ Re₂O₇ Re₂O₇ Re₂O₇Mg₃Mn₃—B₂O₁₀ Co/ Sb/ W/ V/ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀Mg₃Mn₃—B₂O₁₀ Mg₃(BO₃)₂ Co/ Sb/ W/ V/ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂Mg₃(BO₃)₂ NaWO₄ Co/ Sb/ W/ V/ NaWO₄ NaWO₄ NaWO₄ NaWO₄ Mg₆MnO₈ Co/ Sb/ W/V/ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ Mg₆MnO₈ Mn₂O₄ Co/ Sb/ W/ V/ Mn₂O₄ Mn₂O₄ Mn₂O₄Mn₂O₄ (Li,Mg)₆—MnO₈ Co/ Sb/ W/ V/ (Li,Mg)₆—MnO₈ (Li,Mg)₆—MnO₈(Li,Mg)₆—MnO₈ (Li,Mg)₆—MnO₈ Na₄P₂O₇ Co/ Sb/ W/ V/ Na₄P₂O₇ Na₄P₂O₇Na₄P₂O₇ Na₄P₂O₇ Mo₂O₈ Co/ Sb/ W/ V/ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mn₃O₄/WO₄Co/ Sb/ W/ V/ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Na₂WO₄ Co/ Sb/ W/V/ Na₂WO₄ Na₂WO₄ Na₂WO₄ Na₂WO₄ Zr₂Mo₂O₈ Co/ Sb/ W/ V/ Zr₂Mo₂O₈ Zr₂Mo₂O₈Zr₂Mo₂O₈ Zr₂Mo₂O₈ NaMnO₄—/ Co/ Sb/ W/ V/ MgO NaMnO₄—/ NaMnO₄—/ NaMnO₄—/NaMnO₄—/ MgO MgO MgO MgO Na₁₀Mn—W₅O₁₇ Co/ Sb/ W/ V/ Na₁₀Mn—W₅O₁₇Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Dop NW Ag Te Pd Ir Li₂O Ag/ Te/Pd/ Ir/ Li₂O Li₂O Li₂O Li₂O Na₂O Ag/ Te/ Pd/ Ir/ Na₂O Na₂O Na₂O Na₂O K₂OAg/ Te/ Pd/ Ir/ K₂O K₂O K₂O K₂O Rb₂O Ag/ Te/ Pd/ Ir/ Rb₂O Rb₂O Rb₂O Rb₂OCs₂O Ag/ Te/ Pd/ Ir/ Cs₂O Cs₂O Cs₂O Cs₂O BeO Ag/ Te/ Pd/ Ir/ BeO BeO BeOBeO MgO Ag/ Te/ Pd/ Ir/ MgO MgO MgO MgO CaO Ag/ Te/ Pd/ Ir/ CaO CaO CaOCaO SrO Ag/ Te/ Pd/ Ir/ SrO SrO SrO SrO BaO Ag/ Te/ Pd/ Ir/ BaO BaO BaOBaO Sc₂O₃ Ag/ Te/ Pd/ Ir/ Sc₂O₃ Sc₂O₃ Sc₂O₃ Sc₂O₃ Y₂O₃ Ag/ Te/ Pd/ Ir/Y₂O₃ Y₂O₃ Y₂O₃ Y₂O₃ La₂O₃ Ag/ Te/ Pd/ Ir/ La₂O₃ La₂O₃ La₂O₃ La₂O₃ CeO₂Ag/ Te/ Pd/ Ir/ CeO₂ CeO₂ CeO₂ CeO₂ Ce₂O₃ Ag/ Te/ Pd/ Ir/ Ce₂O₃ Ce₂O₃Ce₂O₃ Ce₂O₃ Pr₂O₃ Ag/ Te/ Pd/ Ir/ Pr₂O₃ Pr₂O₃ Pr₂O₃ Pr₂O₃ Nd₂O₃ Ag/ Te/Pd/ Ir/ Nd₂O₃ Nd₂O₃ Nd₂O₃ Nd₂O₃ Sm₂O₃ Ag/ Te/ Pd/ Ir/ Sm₂O₃ Sm₂O₃ Sm₂O₃Sm₂O₃ Eu₂O₃ Ag/ Te/ Pd/ Ir/ Eu₂O₃ Eu₂O₃ Eu₂O₃ Eu₂O₃ Gd₂O₃ Ag/ Te/ Pd/Ir/ Gd₂O₃ Gd₂O₃ Gd₂O₃ Gd₂O₃ Tb₂O₃ Ag/ Te/ Pd/ Ir/ Tb₂O₃ Tb₂O₃ Tb₂O₃Tb₂O₃ TbO₂ Ag/ Te/ Pd/ Ir/ TbO₂ TbO₂ TbO₂ TbO₂ Tb₆O₁₁ Ag/ Te/ Pd/ Ir/Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Tb₆O₁₁ Dy₂O₃ Ag/ Te/ Pd/ Ir/ Dy₂O₃ Dy₂O₃ Dy₂O₃Dy₂O₃ Ho₂O₃ Ag/ Te/ Pd/ Ir/ Ho₂O₃ Ho₂O₃ Ho₂O₃ Ho₂O₃ Er₂O₃ Ag/ Te/ Pd/Ir/ Er₂O₃ Er₂O₃ Er₂O₃ Er₂O₃ Tm₂O₃ Ag/ Te/ Pd/ Ir/ Tm₂O₃ Tm₂O₃ Tm₂O₃Tm₂O₃ Yb₂O₃ Ag/ Te/ Pd/ Ir/ Yb₂O₃ Yb₂O₃ Yb₂O₃ Yb₂O₃ Lu₂O₃ Ag/ Te/ Pd/Ir/ Lu₂O₃ Lu₂O₃ Lu₂O₃ Lu₂O₃ Ac₂O₃ Ag/ Te/ Pd/ Ir/ Ac₂O₃ Ac₂O₃ Ac₂O₃Ac₂O₃ Th₂O₃ Ag/ Te/ Pd/ Ir/ Th₂O₃ Th₂O₃ Th₂O₃ Th₂O₃ ThO₂ Ag/ Te/ Pd/ Ir/ThO₂ ThO₂ ThO₂ ThO₂ Pa₂O₃ Ag/ Te/ Pd/ Ir/ Pa₂O₃ Pa₂O₃ Pa₂O₃ Pa₂O₃ PaO₂Ag/ Te/ Pd/ Ir/ PaO₂ PaO₂ PaO₂ PaO₂ TiO₂ Ag/ Te/ Pd/ Ir/ TiO₂ TiO₂ TiO₂TiO₂ TiO Ag/ Te/ Pd/ Ir/ TiO TiO TiO TiO Ti₂O₃ Ag/ Te/ Pd/ Ir/ Ti₂O₃Ti₂O₃ Ti₂O₃ Ti₂O₃ Ti₃O Ag/ Te/ Pd/ Ir/ Ti₃O Ti₃O Ti₃O Ti₃O Ti₂O Ag/ Te/Pd/ Ir/ Ti₂O Ti₂O Ti₂O Ti₂O Ti₃O₅ Ag/ Te/ Pd/ Ir/ Ti₃O₅ Ti₃O₅ Ti₃O₅Ti₃O₅ Ti₄O₇ Ag/ Te/ Pd/ Ir/ Ti₄O₇ Ti₄O₇ Ti₄O₇ Ti₄O₇ ZrO₂ Ag/ Te/ Pd/ Ir/ZrO₂ ZrO₂ ZrO₂ ZrO₂ HfO₂ Ag/ Te/ Pd/ Ir/ HfO₂ HfO₂ HfO₂ HfO₂ VO Ag/ Te/Pd/ Ir/ VO VO VO VO V₂O₃ Ag/ Te/ Pd/ Ir/ V₂O₃ V₂O₃ V₂O₃ V₂O₃ VO₂ Ag/ Te/Pd/ Ir/ VO₂ VO₂ VO₂ VO₂ V₂O₅ Ag/ Te/ Pd/ Ir/ V₂O₅ V₂O₅ V₂O₅ V₂O₅ V₃O₇Ag/ Te/ Pd/ Ir/ V₃O₇ V₃O₇ V₃O₇ V₃O₇ V₄O₉ Ag/ Te/ Pd/ Ir/ V₄O₉ V₄O₉ V₄O₉V₄O₉ V₆O₁₃ Ag/ Te/ Pd/ Ir/ V₆O₁₃ V₆O₁₃ V₆O₁₃ V₆O₁₃ NbO Ag/ Te/ Pd/ Ir/NbO NbO NbO NbO NbO₂ Ag/ Te/ Pd/ Ir/ NbO₂ NbO₂ NbO₂ NbO₂ Nb₂O₅ Ag/ Te/Pd/ Ir/ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₂O₅ Nb₈O₁₉ Ag/ Te/ Pd/ Ir/ Nb₈O₁₉ Nb₈O₁₉Nb₈O₁₉ Nb₈O₁₉ Nb₁₆O₃₈ Ag/ Te/ Pd/ Ir/ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₆O₃₈Nb₁₂O₂₉ Ag/ Te/ Pd/ Ir/ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₄₇O₁₁₆ Ag/ Te/Pd/ Ir/ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Ta₂O₅ Ag/ Te/ Pd/ Ir/ Ta₂O₅Ta₂O₅ Ta₂O₅ Ta₂O₅ CrO Ag/ Te/ Pd/ Ir/ CrO CrO CrO CrO Cr₂O₃ Ag/ Te/ Pd/Ir/ Cr₂O₃ Cr₂O₃ Cr₂O₃ Cr₂O₃ CrO₂ Ag/ Te/ Pd/ Ir/ CrO₂ CrO₂ CrO₂ CrO₂CrO₃ Ag/ Te/ Pd/ Ir/ CrO₃ CrO₃ CrO₃ CrO₃ Cr₈O₂₁ Ag/ Te/ Pd/ Ir/ Cr₈O₂₁Cr₈O₂₁ Cr₈O₂₁ Cr₈O₂₁ MoO₂ Ag/ Te/ Pd/ Ir/ MoO₂ MoO₂ MoO₂ MoO₂ MoO₃ Ag/Te/ Pd/ Ir/ MoO₃ MoO₃ MoO₃ MoO₃ W₂O₃ Ag/ Te/ Pd/ Ir/ W₂O₃ W₂O₃ W₂O₃ W₂O₃WoO₂ Ag/ Te/ Pd/ Ir/ WoO₂ WoO₂ WoO₂ WoO₂ WoO₃ Ag/ Te/ Pd/ Ir/ WoO₃ WoO₃WoO₃ WoO₃ MnO Ag/ Te/ Pd/ Ir/ MnO MnO MnO MnO Mn/Mg/O Ag/ Te/ Pd/ Ir/Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn/Mg/O Mn₃O₄ Ag/ Te/ Pd/ Ir/ Mn₃O₄ Mn₃O₄ Mn₃O₄Mn₃O₄ Mn₂O₃ Ag/ Te/ Pd/ Ir/ Mn₂O₃ Mn₂O₃ Mn₂O₃ Mn₂O₃ MnO₂ Ag/ Te/ Pd/ Ir/MnO₂ MnO₂ MnO₂ MnO₂ Mn₂O₇ Ag/ Te/ Pd/ Ir/ Mn₂O₇ Mn₂O₇ Mn₂O₇ Mn₂O₇ ReO₂Ag/ Te/ Pd/ Ir/ ReO₂ ReO₂ ReO₂ ReO₂ ReO₃ Ag/ Te/ Pd/ Ir/ ReO₃ ReO₃ ReO₃ReO₃ Re₂O₇ Ag/ Te/ Pd/ Ir/ Re₂O₇ Re₂O₇ Re₂O₇ Re₂O₇ Mg₃Mn₃—B₂O₁₀ Ag/ Te/Pd/ Ir/ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃(BO₃)₂Ag/ Te/ Pd/ Ir/ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂ Mg₃(BO₃)₂ NaWO₄ Ag/ Te/Pd/ Ir/ NaWO₄ NaWO₄ NaWO₄ NaWO₄ Mg₆MnO₈ Ag/ Te/ Pd/ Ir/ Mg₆MnO₈ Mg₆MnO₈Mg₆MnO₈ Mg₆MnO₈ Mn₂O₄ Ag/ Te/ Pd/ Ir/ Mn₂O₄ Mn₂O₄ Mn₂O₄ Mn₂O₄(Li,Mg)₆—MnO₈ Ag/ Te/ Pd/ Ir/ (Li,Mg)₆—MnO₈ (Li,Mg)₆—MnO₈ (Li,Mg)₆—MnO₈(Li,Mg)₆—MnO₈ Na₄P₂O₇ Ag/ Te/ Pd/ Ir/ Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇ Na₄P₂O₇Mo₂O₈ Ag/ Te/ Pd/ Ir/ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mo₂O₈ Mn₃O₄/WO₄ Ag/ Te/ Pd/ Ir/Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Mn₃O₄/WO₄ Na₂WO₄ Ag/ Te/ Pd/ Ir/ Na₂WO₄Na₂WO₄ Na₂WO₄ Na₂WO₄ Zr₂Mo₂O₈ Ag/ Te/ Pd/ Ir/ Zr₂Mo₂O₈ Zr₂Mo₂O₈ Zr₂Mo₂O₈Zr₂Mo₂O₈ NaMnO₄—/ Ag/ Te/ Pd/ Ir/ MgO NaMnO₄—/ NaMnO₄—/ NaMnO₄—/NaMnO₄—/ MgO MgO MgO MgO Na₁₀Mn—W₅O₁₇ Ag/ Te/ Pd/ Ir/ Na₁₀Mn—W₅O₁₇Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇

TABLE 8 NANOWIRES (NW) DOPED WITH SPECIFIC DOPANTS (DOP) Dop NW Mn TiLi₂O Mn/ Ti/ Li₂O Li₂O Na₂O Mn/ Ti/ Na₂O Na₂O K₂O Mn/ Ti/ K₂O K₂O Rb₂OMn/ Ti/ Rb₂O Rb₂O Cs₂O Mn/ Ti/ Cs₂O Cs₂O BeO Mn/ Ti/ BeO BeO MgO Mn/ Ti/MgO MgO CaO Mn/ Ti/ CaO CaO SrO Mn/ Ti/ SrO SrO BaO Mn/ Ti/ BaO BaOSc₂O₃ Mn/ Ti/ Sc₂O₃ Sc₂O₃ Y₂O₃ Mn/ Ti/ Y₂O₃ Y₂O₃ La₂O₃ Mn/ Ti/ La₂O₃La₂O₃ CeO₂ Mn/ Ti/ CeO₂ CeO₂ Ce₂O₃ Mn/ Ti/ Ce₂O₃ Ce₂O₃ Pr₂O₃ Mn/ Ti/Pr₂O₃ Pr₂O₃ Nd₂O₃ Mn/ Ti/ Nd₂O₃ Nd₂O₃ Sm₂O₃ Mn/ Ti/ Sm₂O₃ Sm₂O₃ Eu₂O₃Mn/ Ti/ Eu₂O₃ Eu₂O₃ Gd₂O₃ Mn/ Ti/ Gd₂O₃ Gd₂O₃ Tb₂O₃ Mn/ Ti/ Tb₂O₃ Tb₂O₃TbO₂ Mn/ Ti/ TbO₂ TbO₂ Tb₆O₁₁ Mn/ Ti/ Tb₆O₁₁ Tb₆O₁₁ Dy₂O₃ Mn/ Ti/ Dy₂O₃Dy₂O₃ Ho₂O₃ Mn/ Ti/ Ho₂O₃ Ho₂O₃ Er₂O₃ Mn/ Ti/ Er₂O₃ Er₂O₃ Tm₂O₃ Mn/ Ti/Tm₂O₃ Tm₂O₃ Yb₂O₃ Mn/ Ti/ Yb₂O₃ Yb₂O₃ Lu₂O₃ Mn/ Ti/ Lu₂O₃ Lu₂O₃ Ac₂O₃Mn/ Ti/ Ac₂O₃ Ac₂O₃ Th₂O₃ Mn/ Ti/ Th₂O₃ Th₂O₃ ThO₂ Mn/ Ti/ ThO₂ ThO₂Pa₂O₃ Mn/ Ti/ Pa₂O₃ Pa₂O₃ PaO₂ Mn/ Ti/ PaO₂ PaO₂ TiO₂ Mn/ Ti/ TiO₂ TiO₂TiO Mn/ Ti/ TiO TiO Ti₂O₃ Mn/ Ti/ Ti₂O₃ Ti₂O₃ Ti₃O Mn/ Ti/ Ti₃O Ti₃OTi₂O Mn/ Ti/ Ti₂O Ti₂O Ti₃O₅ Mn/ Ti/ Ti₃O₅ Ti₃O₅ Ti₄O₇ Mn/ Ti/ Ti₄O₇Ti₄O₇ ZrO₂ Mn/ Ti/ ZrO₂ ZrO₂ HfO₂ Mn/ Ti/ HfO₂ HfO₂ VO Mn/ Ti/ VO VOV₂O₃ Mn/ Ti/ V₂O₃ V₂O₃ VO₂ Mn/ Ti/ VO₂ VO₂ V₂O₅ Mn/ Ti/ V₂O₅ V₂O₅ V₃O₇Mn/ Ti/ V₃O₇ V₃O₇ V₄O₉ Mn/ Ti/ V₄O₉ V₄O₉ V₆O₁₃ Mn/ Ti/ V₆O₁₃ V₆O₁₃ NbOMn/ Ti/ NbO NbO NbO₂ Mn/ Ti/ NbO₂ NbO₂ Nb₂O₅ Mn/ Ti/ Nb₂O₅ Nb₂O₅ Nb₈O₁₉Mn/ Ti/ Nb₈O₁₉ Nb₈O₁₉ Nb₁₆O₃₈ Mn/ Ti/ Nb₁₆O₃₈ Nb₁₆O₃₈ Nb₁₂O₂₉ Mn/ Ti/Nb₁₂O₂₉ Nb₁₂O₂₉ Nb₄₇O₁₁₆ Mn/ Ti/ Nb₄₇O₁₁₆ Nb₄₇O₁₁₆ Ta₂O₅ Mn/ Ti/ Ta₂O₅Ta₂O₅ CrO Mn/ Ti/ CrO CrO Cr₂O₃ Mn/ Ti/ Cr₂O₃ Cr₂O₃ CrO₂ Mn/ Ti/ CrO₂CrO₂ CrO₃ Mn/ Ti/ CrO₃ CrO₃ Cr₈O₂₁ Mn/ Ti/ Cr₈O₂₁ Cr₈O₂₁ MoO₂ Mn/ Ti/MoO₂ MoO₂ MoO₃ Mn/ Ti/ MoO₃ MoO₃ W₂O₃ Mn/ Ti/ W₂O₃ W₂O₃ WoO₂ Mn/ Ti/WoO₂ WoO₂ WoO₃ Mn/ Ti/ WoO₃ WoO₃ MnO Mn/ Ti/ MnO MnO Mn/Mg/O Mn/ Ti/Mn/Mg/O Mn/Mg/O Mn₃O₄ Mn/ Ti/ Mn₃O₄ Mn₃O₄ Mn₂O₃ Mn/ Ti/ Mn₂O₃ Mn₂O₃ MnO₂Mn/ Ti/ MnO₂ MnO₂ Mn₂O₇ Mn/ Ti/ Mn₂O₇ Mn₂O₇ ReO₂ Mn/ Ti/ ReO₂ ReO₂ ReO₃Mn/ Ti/ ReO₃ ReO₃ Re₂O₇ Mn/ Ti/ Re₂O₇ Re₂O₇ Mg₃Mn₃—B₂O₁₀ Mn/ Ti/Mg₃Mn₃—B₂O₁₀ Mg₃Mn₃—B₂O₁₀ Mg₃(BO₃)₂ Mn/ Ti/ Mg₃(BO₃)₂ Mg₃(BO₃)₂ NaWO₄Mn/ Ti/ NaWO₄ NaWO₄ Mg₆MnO₈ Mn/ Ti/ Mg₆MnO₈ Mg₆MnO₈ Mn₂O₄ Mn/ Ti/ Mn₂O₄Mn₂O₄ (Li,Mg)₆—MnO₈ Mn/ Mn/ (Li,Mg)₆—MnO₈ (Li,Mg)₆—MnO₈ Na₄P₂O₇ Mn/ Ti/Na₄P₂O₇ Na₄P₂O₇ Mo₂O₈ Mn/ Ti/ Mo₂O₈ Mo₂O₈ Mn₃O₄/WO₄ Mn/ Ti/ Mn₃O₄/WO₄Mn₃O₄/WO₄ Na₂WO₄ Mn/ Ti/ Na₂WO₄ Na₂WO₄ Zr₂Mo₂O₈ Mn/ Ti/ Zr₂Mo₂O₈Zr₂Mo₂O₈ NaMnO₄—/ Mn/ Ti/ MgO NaMnO₄—/ NaMnO₄—/ MgO MgO Na₁₀Mn—W₅O₁₇ Mn/Ti/ Na₁₀Mn—W₅O₁₇ Na₁₀Mn—W₅O₁₇

As used in Table 1-8 and throughout the specification, a nanowirecomposition represented by E¹/E²E³ etc., wherein E¹, E² and E³ are eachindependently an element or a compound comprising one or more elements,refers to a nanowire composition comprised of a mixture of E¹, E² andE³. E¹/E²E³ etc. are not necessarily present in equal amounts and neednot form a bond with one another. For example, a nanowire comprisingLi/MgO refers to a nanowire comprising Li and MgO, for example, Li/MgOmay refer to a MgO nanowire doped with Li. By way of another example, ananowire comprising NaMnO₄/MgO refers to a nanowire comprised of amixture of NaMnO₄ and MgO. Dopants may be added in suitable form. Forexample in a lithium doped magnesium oxide nanowire (Li/MgO), the Lidopant can be incorporated in the form of Li₂O, Li₂CO₃, LiOH, or othersuitable forms. Li may be fully incorporated in the MgO crystal lattice(e.g., (Li,Mg)O) as well. Dopants for other nanowires may beincorporated analogously.

In some more specific embodiments, the dopant is selected from Li, Baand Sr. In other specific embodiments, the nanowires comprise Li/MgO,Ba/MgO, Sr/La₂O₃, Ba/La₂O₃, Mn/Na₂WO₄, Mn₂O₃/Na₂WO₄, Mn₃O₄/Na₂WO₄,Mg₆MnO₈, Li/B/Mg₆MnO₈, Na/B/Mg₆MnO₈, Zr₂Mo₂O₈ or NaMnO₄/MgO.

In some other specific embodiments, the nanowire comprises a mixed oxideof Mn and Mg with or without B and with or without Li. Additionaldopants for such nanowires may comprise doping elements selected fromGroup 1 and 2 and groups 7-13. The dopants may be present as singledopants or in combination with other dopants. In certain specificembodiments of nanowires comprising a mixed oxide of Mn and Mg with orwithout B and with or without Li., the dopant comprises a combination ofelements from group 1 and group 8-11.

Nanowires comprising mixed oxides of Mn and Mg are well suited forincorporation of dopants because magnesium atoms can be easilysubstituted by other atoms as long as their size is comparable withmagnesium. A family of “doped” Mg₆MnO₈ compounds with the compositionM_((x))Mg_((6-x))MnO₈, wherein each M is independently a dopant asdefined herein and x is 0 to 6, can thus be created. The oxidation stateof Mn can be tuned by selecting different amounts (i.e., differentvalues of x) of M with different oxidation states, for exampleLi_((x))Mg_((6-x))MnO₈ would contain a mixture of Mn(IV) and Mn(V) withx<1 and a mixture that may include Mn(V), Mn(VI), Mn(VII) with x>1. Themaximum value of x depends on the ability of a particular atom M to beincorporated in the Mg₆MnO₈ crystal structure and therefore variesdepending on M. It is believed that the ability to tune the manganeseoxidation state as described above could have advantageous effect on thecatalytic activity of the disclosed nanowires.

Examples of nanowires comprising Li/Mn/Mg/B and an additional dopantinclude; Li/Mn/Mg/B doped with Co; Li/Mn/Mg/B doped with Na, Li/Mn/Mg/Bdoped with Be; Li/Mn/Mg/B doped with Al; Li/Mn/Mg/B doped with Hf;Li/Mn/Mg/B doped with Zr; Li/Mn/Mg/B doped with Zn; Li/Mn/Mg/B dopedwith Rh and Li/Mn/Mg/B doped with Ga. Nanowires comprising Li/Mn/Mg/Bdoped with different combinations of these dopants are also provided.For example, in some embodiments the Li/Mn/Mg/B nanowires are doped withNa and Co. In other embodiments, the Li/Mn/Mg/B nanowires are doped withGa and Na.

In other embodiments, nanowires comprising Mn/W with or without dopantsare provided. For example, the present inventors have found through highthroughput testing that nanowires comprising Mn/W and various dopantsare good catalysts in the OCM reaction. Accordingly, in someembodiments, the Mn/W nanowires are doped with Ba. In other embodiments,the Mn/W nanowires are doped with Be. In yet other embodiments, the Mn/Wnanowires are doped with Te.

In any of the above embodiments, the Mn/W nanowires may comprise a SiO₂support. Alternatively, the use of different supports such as ZrO₂, HfO₂and In₂O₃ in any of the above embodiments has been shown to promote OCMactivity at reduced temperature compared to the same catalyst supportedon silica with limited reduction in selectivity.

Nanowires comprising rare earth oxides or Yttria doped with variouselements are also effective catalysts in the OCM reaction. In certainspecific embodiments, the rare earth oxide or oxy-hydroxide can be anyrare earth, preferably La, Nd, Eu, Sm, Yb, Gd. In certain embodiments ofthe nanowires comprising rare earth elements or yttria, the dopantcomprises alkali earth (group 2) elements. The degree of effectivenessof a particular dopant is a function of the rare earth used and theconcentration of the alkali earth dopant. In addition to Alkali earthelements, further embodiments of the rare earth or yttria nanowiresinclude embodiments wherein the nanowires comprise alkali elements asdopants which further promote the selectivity of the OCM catalyticactivity of the doped material. In yet other embodiments of theforegoing, the nanowires comprise both an alkali element and alkaliearth element as dopant. In still further embodiments, an additionaldopant can be selected from an additional rare earth and groups 3, 4, 8,9, 10, 13, 14.

The foregoing rare earth or yttria catalyst may be doped prior to, orafter formation of the rare earth or yttria oxide. In one, the rareearth or yttria salt is mixed with the precursor salt to form a solutionor a slurry which is dried and then calcined in a range of 400° C. to900° C., or between 500° C. and 700° C. In another embodiment, the rareearth or yttria oxide is formed first through calcination of a rareearth or yttria salt and then contacted with a solution comprising thedoping element prior to drying and calcination between 300° C. and 800°C., or between 400° C. and 700° C.

In other embodiments, the nanowires comprise La₂O₃ or LaO_(y)(OH)_(x),wherein y ranges from 0 to 1.5, x ranges from 0 to 3 and 2y+x=3, dopedwith Na, Mg, Ca, Sr, Ga, Sc, Y, Zr, In, Nd, Eu, Sm, Ce, Gd orcombinations thereof. In yet further embodiments, the La₂O₃ orLaO_(y)(OH)_(x) nanowires are doped with binary dopant combinations, forexample Eu/Na; Eu/Gd; Ca/Na; Eu/Sm; Eu/Sr; Mg/Sr; Ce/Mg; Gd/Sm, Mg/Na,Mg/Y, Ga/Sr, Nd/Mg, Gd/Na or Sm/Na. In some other embodiments, the La₂O₃or LaO_(y)(OH)_(x) nanowires are doped with a binary dopant combination,for example Ca—Mg—Na.

In other embodiments, the nanowires comprise Nd₂O₃ or NdO_(y)(OH)_(x),wherein y ranges from 0 to 1.5, x ranges from 0 to 3 and 2y+x=3, dopedwith Sr, Ca, Rb, Li, Na or combinations thereof. In certain otherembodiments, the Nd₂O₃ or NdO_(y)(OH)_(x) nanowires are doped withbinary dopant combinations, for example Ca/Sr or Rb/Sr, Ta/Sr or Al/Sr.

In still other examples of doped nanowires, the nanowires comprise Yb₂O₃or YbO_(y)(OH)_(x), wherein y ranges from 0 to 1.5, x ranges from 0 to 3and 2y+x=3, doped with Sr, Ca, Ba, Nd or combinations thereof. Incertain other embodiments, the Yb₂O₃ or YbO_(y)(OH)_(x) OCM nanowiresare doped with a binary combination, for example of Sr/Nd.

Still other examples of doped nanowires Eu₂O₃ or EuO_(y)(OH)_(x)nanowires, wherein y ranges from 0 to 1.5, x ranges from 0 to 3 and2y+x=3, doped with Sr, Ba, Sm, Gd, Na or combinations thereof or abinary dopant combination, for example Sr/Na or Sm/Na.

Example of dopants for Sm₂O₃ or SmO_(y)(OH)_(x) nanowires, wherein x andy are each independently an integer from 1 to 10, include Sr, andexamples of dopants for Y₂O₃ or YO_(y)(OH)_(x) nanowires, wherein yranges from 0 to 1.5, x ranges from 0 to 3 and 2y+x=3, comprise Ga, La,Nd or combinations thereof. In certain other embodiments, the Y₂O₃ orYO_(y)(OH)_(x) nanowires comprise a binary dopant combination, forexample Sr/Nd, Eu/Y or Mg/Nd or a tertiary dopant combination, forexample Mg/Nd/Fe.

Rare earth nanowires which without doping have low OCM selectivity canbe greatly improved by doping to reduce their combustion activity. Inparticular, nanowires comprising CeO₂ and Pr₂O₃ tend to have strongtotal oxidation activity for methane, however doping with additionalrare earth elements can significantly moderate the combustion activityand improve the overall utility of the catalyst. Example of dopantswhich improving the selectivity for Pr₂O₃ or PrO_(y)(OH)_(x) nanowires,wherein y ranges from 0 to 1.5, x ranges from 0 to 3 and 2y+x=3,comprise binary dopants, for example Nd/Mg, La/Mg or Yb/Sr.

In some embodiments, dopants are present in the nanowires in, forexample, less than 50 at %, less than 25 at %, less than 10 at %, lessthan 5 at % or less than 1 at %.

In other embodiments of the nanowires, the atomic ratio (w/w) of the oneor more metal elements selected from Groups I-7 and lanthanides andactinides in the form of an oxide and the dopant ranges from 1:1 to10,000:1, 1:1 to 1,000:1 or 1:1 to 500:1.

In further embodiments, the nanowires comprise one or more metalelements from Group2 in the form of an oxide and a dopant from Group I.In further embodiments, the nanowires comprise magnesium and lithium. Inother embodiments, the nanowires comprise one or more metal elementsfrom Group2 and a dopant from Group 2, for example, in some embodiments,the nanowires comprise magnesium oxide and barium. In anotherembodiment, the nanowires comprise an element from the lanthanides inthe form of an oxide and a dopant from Group 1 or Group 2. In furtherembodiments, the nanowires comprise lanthanum and strontium.

Various methods for preparing doped nanowires are provided. In oneembodiment, the doped nanowires can be prepared by co-precipitating ananowire metal oxide precursor and a dopant precursor. In theseembodiments, the doping element may be directly incorporated into thenanowire.

Template Directed Synthesis of Nanowires

In some embodiments, the nanowires can be prepared in a solution phaseusing an appropriate template. In this context, an appropriate templatecan be any synthetic or natural material, or combination thereof, thatprovides nucleation sites for binding ions (e.g. metal element ionsand/or hydroxide or other anions) and causing the growth of a nanowire.The templates can be selected such that certain control of thenucleation sites, in terms of their composition, quantity and locationcan be achieved in a statistically significant manner. The templates aretypically linear or anisotropic in shape, thus directing the growth of ananowire.

In contrast to other template directed preparation of nanowires, thepresent nanowires are generally not prepared from nanoparticlesdeposited on a template in a reduced state which are then heat treatedand fused into a nanowire. Such methods are not generally applicable tonanowires comprising one or more elements from any of Groups 1 through7, lanthanides, actinides or combinations thereof. Instead, thenanowires are prepared by nucleation of an oxidized metal element (e.g.,in the form of a metal salt) and subsequent growth of nanowire. Thenanowires are then generally calcined to produce the desired oxide, butannealing of nanoparticles is not necessary to form the nanowires.

1. Biological Template

Because peptide sequences have been shown to have specific and selectivebinding affinity for many different types of metal element ions,biological templates incorporating peptide sequences as nucleation sitesare preferred. Moreover, biological templates can be engineered tocomprise pre-determined nucleation sites in pre-determined spatialrelationships (e.g., separated by a few to tens of nanometers).

Both wild type and genetically engineered biological templates can beused. As discussed herein, biological templates such as proteins andbacteriophage can be engineered based on genetics to ensure control overthe type of nucleation sites (e.g., by controlling the peptidesequences), their locations on the templates and their respectivedensity and/or ratio to other nucleation sites. See, e.g., Mao, C. B. etal., (2004) Science, 303, 213-217; Belcher, A. et al., (2002) Science296, 892-895; Belcher, A. et al., (2000) Nature 405 (6787) 665-668;Reiss et al., (2004) Nanoletters, 4 (6), 1127-1132, Flynn, C. et al.,(2003) J. Mater. Sci., 13, 2414-2421; Mao, C. B. et al., (2003) PNAS,100 (12), 6946-6951, which references are hereby incorporated byreference in their entireties. This allows for the ability to controlthe composition and distribution of the nucleation sites on thebiological template.

Thus, biological templates may be particularly advantageous for acontrolled growth of nanowires. Biological templates can be biomolecules(e.g., proteins) as well as multi-molecular structures of a biologicalorigin, including, for example, bacteriophage, virus, amyloid fiber, andcapsid.

(a) Biomolecules

In certain embodiments, the biological templates are biomolecules. Inmore specific embodiments, the biological templates are anisotropicbiomolecules. Typically, a biomolecule comprises a plurality of subunits(building blocks) joined together in a sequence via chemical bonds. Eachsubunit comprises at least two reactive groups such as hydroxyl,carboxylic acid and amino groups, which enable the bond formations thatinterconnect the subunits. Examples of the subunits include, but are notlimited to: amino acids (both natural and synthetic) and nucleotides.Accordingly, in some embodiments, the biomolecule template is a peptide,protein, nucleic acid, polynucleotide, amino acid, antibody, enzyme, orsingle-stranded or double-stranded nucleic acid or any modified and/ordegraded forms thereof.

Because protein synthesis can be genetically directed, proteins can bereadily manipulated and functionalized to contain desired peptidesequences (i.e., nucleation sites) at desired locations within theprimary structure of the protein. The protein can then be assembled toprovide a template.

Thus, in various embodiments, the templates are biomolecules are nativeproteins or proteins that can be engineered to have nucleation sites forspecific ions.

(b) Baceteriophage

In one particular embodiment, the biological template comprises a M13bacteriophage which has or can be engineered to have one or moreparticular peptide sequences bound onto the coat proteins. FIG. 6schematically shows a filamentous bacteriophage 400, in which asingle-stranded DNA core 410 is surrounded by a proteinaceous coat 420.The coat is composed mainly of pVIII proteins 424 that cover the lengthof the bacteriophage. The ends of the bacteriophage are capped by minorcoat proteins 430 (pIII), 440 (pVI), 450 (pVII) and 460 (pIX).

Using genetic engineering, a library of diverse, novel peptide sequences(up to 10¹² unique peptides) can be expressed on the surface of thephage, so that each individual phage displays at least one uniquepeptide sequence. These externally facing peptide sequences can betested, through the iterative steps of screening, amplification andoptimization, for the ability to control nucleation and growth ofspecific catalytic nanowires.

For example, in a further embodiment peptide sequences having one ormore particular nucleation sites specific for various ions are boundonto the coat proteins. For example, in one embodiment, the coat proteinis pVIII with peptide sequences having one or more particular nucleationsites specific for various ions bound thereto. In other furtherembodiments, the peptide sequences bound to the coat protein comprise 2or more amino acids, 5 or more amino acids, 10 or more amino acids, 20or more amino acids, or 40 or more amino acids. In other embodiments,the peptide sequences bound to the coat protein comprise between 2 and40 amino acids, between 5 and 20 amino acids, or between 7 and 12 aminoacids.

One of the approaches to obtain different types of M13 bacteriophage isto modify the viral genetic code in order to change the amino acidsequence of the phage coating protein pVIII. The changes in sequenceonly affect the last amino acids of the pVIII protein, which are theones that make the surface of the M13 phage, while the first 45 aminoacids are left unchanged so that the packing of the pVIII proteinsaround the phage is not compromised. By changing the outer amino acidson the pVIII protein, the surface characteristics of the phage can betailored to higher affinities to specific metal ions and thus promotingselective growth of specific inorganic materials on the phage surface.

(c) Amyloid Fibers

In another embodiment, amyloid fibers can be used as the biologicaltemplate on which metal ions can nucleate and assemble into a catalyticnanowire. Under certain conditions, one or more normally solubleproteins (i.e., a precursor protein) may fold and assemble into afilamentous structure and become insoluble. Amyloid fibers are typicallycomposed of aggregated β-strands, regardless of the structure origin ofthe precursor protein. As used herein, the precursor protein may containnatural or unnatural amino acids. The precursor protein may be furthermodified with a fatty acid tail.

(d) Virus and Capsid

In further embodiments, a virus or a capsid can be used as a biologicaltemplate. Similar to a bacteriophage, a virus also comprises a proteincoat and a nucleic acid core. In particular, viruses of anisotropicshapes, such as viral fibers, are suitable for nucleating and growingthe catalytic nanowires described herein. Further, a virus can begenetically manipulated to express specific peptides on its coat fordesirable binding to the ions. Viruses that have elongated orfilamentous structures include those that are described in, for example,Christopher Ring, Genetically Engineered Viruses, (Ed) Bios Scientific(2001).

In certain embodiments, the virus may have its genetic materials removedand only the exterior protein coat (capsid) remains as the biologicaltemplate.

2. Nucleation

Nucleation is the process of forming an inorganic nanowire in situ byconverting soluble precursors (e.g., metal salts and anions) intonanocrystals in the presence of a template (e.g., a biologicaltemplate). Typically, the nucleation and growth takes place frommultiple binding sites along the length of the biological template inparallel. The growth continues until a structure encasing the biologicaltemplate is formed. In some embodiments this structure issingle-crystalline. In other embodiments the structure ispolycrystalline, and in other embodiments the structure ispolycrystalline. If desired, upon completion of the synthesis theorganic biological template (e.g., bacteriophage) can be removed bythermal treatment (˜300° C.) in air or oxygen, without significantlyaffecting either the structure or shape of the inorganic material. Inaddition, dopants can be either simultaneously incorporated during thegrowth process or, in another embodiment, dopants can be incorporatedvia impregnation techniques.

(a) Nanowire Growth Methods

FIG. 7 shows a flow chart of a nucleation process for forming a nanowirecomprising a metal oxide. A phage solution is first prepared (block504), to which metal salt precursor comprising metal ions is added(block 510). Thereafter, an anion precursor is added (block 520). It isnoted that, in various embodiments, the additions of the metal ions andanion precursor can be simultaneous or sequentially in any order. Underappropriate conditions (e.g., pH, molar ratio of the phage and metalsalt, molar ratio of the metal ions and anions, addition rate, etc.),the metal ions and anions become bound to the phage, nucleate and growinto a nanowire of M_(m)X_(n)Z_(p) composition (block 524). Followingcalcinations, nanowires comprising M_(m)X_(n) are transformed tonanowires comprising metal oxide (M_(x)O_(y)) (block 530). An optionalstep of doping (block 534) incorporates a dopant (D^(p+)) in thenanowires comprising metal oxide (M_(x)O_(y), wherein x and y are eachindependently a number from 1 to 100.

Thus, one embodiment provides a method for preparing a metal oxidenanowire comprising a plurality of metal oxides (M_(x)O_(y)), the methodcomprising:

a) providing a solution comprising a plurality of biological templates;

(b) introducing at least one metal ion and at least one anion to thesolution under conditions and for a time sufficient to allow fornucleation and growth of a nanowire comprising a plurality of metalsalts (M_(m)X_(n)Z_(p)) on the template; and

(c) converting the nanowire (M_(m)X_(n)Z_(p)) to a metal oxide nanowirecomprising a plurality of metal oxides (M_(x)O_(y)),

wherein:

M is, at each occurrence, independently a metal element from any ofGroups 1 through 7, lanthanides or actinides;

X is, at each occurrence, independently hydroxides, carbonates,bicarbonates, phosphates, hydrogenphosphates, dihydrogenphosphates,sulfates, nitrates or oxalates;

Z is O;

n, m, x and y are each independently a number from 1 to 100; and

p is a number from 0 to 100.

In certain variations of the foregoing, two or more different metal ionsmay be used. This produces nanowires comprising a mixture of two or moremetal oxides. Such nanowires may be advantageous in certain catalyticreactions. For example, in some embodiments a nanowire may comprise twoor more different metal oxides where at least one of the metal oxideshas good OCM activity and at least one metal oxide has good ODHactivity.

In certain embodiments of the above, Applicants have found that it maybe advantageous to perform multiple sequential additions of the metalion, This addition technique may be particularly applicable toembodiments wherein two or more different metal ions are employed toform a mixed nanowire (M1M2X_(x)Y_(y), wherein M1 and M2 are differentmetal elements), which can be converted to M1M2O_(z), for example bycalcination. The slow addition may be performed over any period of time,for example from 1 day to 1 week. In this regard, use of a syringe pumpmay be advantageous. Slow addition of the components help ensure thatthey will nucleate on the biological template instead of non-selectivelyprecipitate.

In various embodiments, the biological templates are phages, as definedherein. In further embodiments, the metal ion is provided by adding oneor more metal salt (as described herein) to the solution. In otherembodiments, the anion is provided by adding one or more anion precursorto the solution. In various embodiments, the metal ion and the anion canbe introduced to the solution simultaneously or sequentially in anyorder. In some embodiments, the nanowire (M_(m)X_(n)Z_(p)) is convertedto a metal oxide nanowire by calcination, which is a thermal treatmentthat transforms or decomposes the M_(m)X_(n)Z_(p) nanowire to a metaloxide. In yet another embodiment, the method further comprises dopingthe metal oxide nanowire with a dopant. Converting the nanowire to ametal oxide generally comprises calcining.

In a variation of the above method, mixed metal oxides can be prepared(as opposed to a mixture of metal oxides). Mixed metal oxides can berepresented by the following formula M1_(w)M2_(x)M3_(y)O_(z), whereinM1, M2 and M3 are each independently absent or a metal element, and w,x, y and z are integers such that the overall charge is balanced. Mixedmetal oxides comprising more than three metals are also contemplated andcan be prepared via an analogous method. Such mixed metal oxides findutility in a variety of the catalytic reactions disclosed herein. Oneexemplary mixed metal oxide is Na₁₀MnW₅O₁₇ (Example 18).

Thus, one embodiment provides a method for preparing a mixed metal oxidenanowire comprising a plurality of mixed metal oxides(M1_(w)M2_(x)M3_(y)O_(z)), the method comprising:

a) providing a solution comprising a plurality of biological templates;

(b) introducing metal salts comprising M1, M2 and M3 to the solutionunder conditions and for a time sufficient to allow for nucleation andgrowth of a nanowire comprising a plurality of the metal salts on thetemplate; and

(c) converting the nanowire to a mixed metal oxide nanowire comprising aplurality of mixed metal oxides (M1_(w)M2_(x)M3_(y)O_(z)), wherein:

M1, M2 and M3 are, at each occurrence, independently a metal elementfrom any of Groups 1 through 7, lanthanides or actinides;

n, m, x and y are each independently a number from 1 to 100; and

p is a number from 0 to 100.

In other embodiments, the present disclosure provides a method forpreparing metal oxide nanowires which may not require a calcinationstep. Thus, in some embodiments the method for preparing metal oxidenanowires comprises:

(a) providing a solution that includes a plurality of biologicaltemplates; and

(b) introducing a compound comprising a metal to the solution underconditions and for a time sufficient to allow for nucleation and growthof a nanowire (M_(m)Y_(n)) on the template;

wherein:

M is a metal element from any of Groups 1 through 7, lanthanides oractinides;

Y is O;

n and m are each independently a number from 1 to 100.

In some specific embodiments of the foregoing method, M is an earlytransition metal, for example V, Nb, Ta, Ti, Zr, Hf, W, Mo or Cr. Inother embodiments, the metal oxide is WO₃. In yet another embodiment,the method further comprises doping the metal oxide nanowire with adopant. In some further embodiments, a reagent is added which convertsthe compound comprising a metal into a metal oxide.

In another embodiment, nanowires are prepared by using metal saltssensitive to water hydrolysis, for example NbCl₅, WCl₆, TiCl₄, ZrCl₄. Atemplate can be placed in ethanol along with the metal salt. Water isthen slowly added to the reaction in order to convert the metals saltsto metal oxide coated template.

By varying the nucleation conditions, including (without limitation):incubation time of phage and metal salt; incubation time of phage andanion; concentration of phage; metal ion concentration, anionconcentration, sequence of adding anion and metal ions; pH; phagesequences; solution temperature in the incubation step and/or growthstep; types of metal precursor salt; types of anion precursor; additionrate; number of additions; amount of metal salt and/or anion precursorper addition, the time that lapses between the additions of the metalsalt and anion precursor, including, e.g., simultaneous (zero lapse) orsequential additions followed by respective incubation times for themetal salt and the anion precursor, stable nanowires of diversecompositions and surface properties can be prepared. For example, incertain embodiments the pH of the nucleation conditions is at least 7.0,at least 8.0, at least 9.0, at least 10.0, at least 11.0, at least 12.0or at least 13.0.

As noted above, the rate of addition of reactants (e.g., metal salt,metal oxide, anion precursor, etc.) is one parameter that can becontrolled and varied to produce nanowires having different properties.During the addition of reactants to a solution containing an existingnanowire and/or a templating material (e.g., phage), a criticalconcentration is reached for which the speed of deposition of solids onthe existing nanowire and/or templating material matches the rate ofaddition of reactants to the reaction mixture. At this point, theconcentration of soluble cation stabilizes and stops rising. Thus,nanowire growth can be controlled and maximized by maintaining the speedof addition of reactants such that near super-saturation concentrationof the cation is maintained. This helps ensure that no undesirablenucleation occurs. If super-saturation of the anion (e.g., hydroxide) isexceeded, a new solid phase can start nucleating which allows fornon-selective solid precipitation, rather than nanowire growth. Thus, inorder to selectively deposit an inorganic layer on an existing nanowireand/or a templating material, the addition rate of reactants should becontrolled to avoid reaching super-saturation of the solution containingthe suspended solids.

Accordingly, in one embodiment, reactant is repeatedly added in smalldoses to slowly build up the concentration of the reactant in thesolution containing the template. In some embodiments, the speed ofaddition of reactant is such that the reactant concentration in thesolution containing the template is near (but less than) the saturationpoint of the reactant. In some other embodiments, the reactant is addedportion wise (i.e., step addition) rather than continuously. In theseembodiments, the amount of reactant in each portion, and the timebetween addition of each portion, is controlled such that the reactantconcentration in the solution containing the template is near (but lessthan) the saturation point of the reactant. In certain embodiments ofthe foregoing, the reactant is a metal cation while in other embodimentsthe reactant is an anion.

Initial formation of nuclei on a template can be obtained by the samemethod described above, wherein the concentration of reactant isincreased until near, but not above, the supersaturation point of thereactant. Such an addition method facilitates nucleation of the solidphase on the template, rather than homogeneous non-seeding nucleation.In some embodiments, it is desirable to use a slower reactant additionspeed during the initial nucleation phase as the super-saturationdepression due to the template might be quite small at this point. Oncethe first layer of solid (i.e., nanowire) is formed on the template, theaddition speed can be increased.

In some embodiments, the addition rate of reactant is controlled suchthat the precipitation rate matches the addition rate of the reactant.In these embodiments, nanowires comprising two or more different metalscan be prepared by controlling the addition rates of two or moredifferent metal cation solutions such that the concentration of eachcation in the templating solution is maintained at or near (but does notexceed) the saturation point for each cation.

In some embodiments, the optimal speed of addition (and step size ifusing step additions) is controlled as a function of temperature. Forexample, in some embodiments the nanowire growth rate is accelerated athigher temperatures. Thus, the addition rate of reactants is adjustedaccording to the temperature of the templating solution.

In other embodiments, modeling (iterative numeric rather than algebraic)of the nanowire growth process is used to determine optimal solutionconcentrations and supernatant re-cycling strategies.

As noted above, the addition rate of reactants can be controlled andmodified to change the properties of the nanowires. In some embodiments,the addition rate of a hydroxide source must be controlled such that thepH of the templating solution is maintained at the desired level. Thismethod may require specialized equipment, and depending on the additionrate, the potential for localized spikes in pH upon addition of thehydroxide source is possible. Thus, in an alternative embodiment thepresent disclosure provides a method wherein the template solutioncomprises a weak base that slowly generates hydroxide in-situ, obviatingthe need for an automated addition sequence.

In the above embodiment, organic epoxides, such as but not limited topropylene oxide and epichlorohydrin, are used to slowly increase thetemplate solution pH without the need for automated pH control. Theepoxides are proton scavengers and undergo an irreversible ring-openingreaction with a nucleophilic anion of the metal oxide precursor (such asbut not limited to Cl⁻ or NO₃ ⁻). The net effect is a slow homogenousraise in pH to form metal hydroxy species in solution that deposit ontothe template surface. In some embodiments, the organic epoxide ispropylene oxide.

An attractive feature of this method is that the organic epoxide can beadded all at once, there is no requirement for subsequent additions oforganic epoxide to grow metal oxide coatings over the course of thereaction. Due to the flexibility of the “epoxide-assisted” coatings, itis anticipated that many various embodiments can be employed to make newtemplated materials (e.g., nanowires). For example, mixed metal oxidenanowires can be prepared by starting with appropriate ratios of metaloxide precursors and propylene oxide in the presence of bacteriophage.In other embodiments, metal oxide deposition on bacteriophage can bedone sequentially to prepare core/shell materials (described in moredetail below).

(b) Metal Salt

As noted above, the nanowires are prepared by nucleation of metal ionsin the presence of an appropriate template, for example, abacteriophage. In this respect, any soluble metal salt may be used asthe precursor of metal ions that nucleate on the template. Soluble metalsalts of the metals from Groups 1 through 7, lanthanides and actinidesare particularly useful and all such salts are contemplated.

In one embodiment, the soluble metal salt comprises chlorides, bromides,iodides, nitrates, sulfates, acetates, oxides, oxyhalides, oxynitrates,phosphates (including hydrogenphosphate and dihydrogenphosphate) oroxalates of metal elements from Groups 1 through 7, lanthanides,actinides or combinations thereof. In more specific embodiments, thesoluble metal salt comprises chlorides, nitrates or sulfates of metalelements from Groups 1 through 7, lanthanides, actinides or combinationsthereof. The present disclosure contemplates all possible chloride,bromide, iodide, nitrate, sulfate, acetate, oxide, oxyhalides,oxynitrates, phosphates (including hydrogenphosphate anddihydrogenphosphate) and oxalate salts of metal elements from Groups 1through 7, lanthanides, actinides or combinations thereof.

In another embodiment, the metal salt comprises LiCl, LiBr, LiI, LiNO₃,Li₂SO₄, LiCO₂CH₃, Li₂C₂O₄, NaCl, NaBr, NaI, NaNO₃, Na₂SO₄, NaCO₂CH₃,Na₂C₂O₄, KCl, KBr, KI, KNO₃, K₂SO₄, KCO₂CH₃, K₂C₂O₄, RbCl, RbBr, RbI,RbNO₃, Rb₂SO₄, RbCO₂CH₃, Rb₂C₂O₄, CsCl, CsBr, CsI, CsNO₃, Cs₂SO₄,CsCO₂CH₃, Cs₂C₂O₄, BeCl₂, BeBr₂, BeI₂, Be(NO₃)₂, BeSO₄, Be(CO₂CH₃)₂,BeC₂O₄, MgCl₂, MgBr₂, MgI₂, Mg(NO₃)₂, MgSO₄, Mg(CO₂CH₃)₂, MgC₂O₄, CaCl₂,CaBr₂, CaI₂, Ca(NO₃)₂, CaSO₄, Ca(CO₂CH₃)₂, CaC₂O₄, SrCl₂, SrBr₂, SrI₂,Sr(NO₃)₂, SrSO₄, Sr(CO₂CH₃)₂, SrC₂O₄, BaCl₂, BaBr₂, BaI₂, Ba(NO₃)₂,BaSO₄, Ba(CO₂CH₃)₂, BaC₂O₄, ScCl₃, ScBr₃, ScI₃, Sc(NO₃)₃, Sc₂(SO₄)₃,Sc(CO₂CH₃)₃, Sc₂(C₂O₄)₃, YCl₃, YBr₃, YI₃, Y(NO₃)₃, Y₂(SO₄)₃, Y(CO₂CH₃)₃,Y₂(O₂O₄)₃, TiCl₄, TiBr₄, TiI₄, Ti(NO₃)₄, Ti(SO₄)₂, Ti(CO₂CH₃)₄,Ti(O₂O₄)₂, ZrCl₄, ZrOCl₂, ZrBr₄, ZrI₄, Zr(NO₃)₄, ZrO(NO₃)₂, Zr(SO₄)₂,Zr(CO₂CH₃)₄, Zr(C₂O₄)₂, HfCl₄, HfBr₄, HfI₄, Hf(NO₃)₄, Hf(SO₄)₂,Hf(CO₂CH₃)₄, Hf(O₂O₄)₂, LaCl₃, LaBr₃, LaI₃, La(NO₃)₃, La₂(SO₄)₃,La(CO₂CH₃)₃, La₂(C₂O₄)₃, WCl₂, WCl₃, WCl₄, WCl₅, WCl₆, WBr₂, WBr₃, WBr₄,WBr₅, WBr₆, WI₂, WI₃, WI₄, WI₅, WI₆, W(NO₃)₂, W(NO₃)₃, W(NO₃)₄, W(NO₃)₅,W(NO₃)₆, W(CO₂CH₃)₂, W(CO₂CH₃)₃, W(CO₂CH₃)₄, W(CO₂CH₃)₅, W(CO₂CH₃)₆,WC₂O₄, W₂(C₂O₄)₃, W(C₂O₄)₂, W₂(C₂O₄)₅, W(C₂O₄)₆, MoCl₄, MnCl₂ MnCl₃,MnBr₂ MnBr₃, MnI₂ MnI₃, Mn(NO₃)₂, Mn(NO₃)₃, MnSO₄, Mn₂(SO₄)₃,Mn(CO₂CH₃)₂, Mn(CO₂CH₃)₃, MnC₂O₄, Mn₂(C₂O₄)₃, MoCl₂, MoCl₃, MoCl₄,MoCl₅, MoBr₂, MoBr₃, MoBr₄, MoBr₅, MoI₂, MoI₃, MoI₄, MoI₅, Mo(NO₃)₂,Mo(NO₃)₃, Mo(NO₃)₄, Mo(NO₃)₅, MoSO₄, Mo₂(SO₄)₃, Mo(SO₄)₂, Mo₂(SO₄)₅,Mo(CO₂CH₃)₂, Mo(CO₂CH₃)₃, Mo(CO₂CH₃)₄, Mo(CO₂CH₃)₅, MoC₂O₄, Mo₂(C₂O₄)₃,Mo(C₂O₄)₂, Mo₂(C₂O₄)₅, VCl, VCl₂, VCl₃, VCl₄, VBr, VBr₂, VBr₃, VBr₄, VI,VI₂, VI₃, VI₄, VNO₃, V(NO₃)₂, V(NO₃)₃, V(NO₃)₄, V₂SO₄, VSO₄, V₂(SO₄)₃,V(SO₄)₄, VCO₂CH₃, V(CO₂CH₃)₂, V(CO₂CH₃)₃, V(CO₂CH₃)₄, V₂O₂O₄, VC₂O₄,V₂(C₂O₄)₃, V(O₂O₄)₄, NdCl₃, NdBr₃, NdI₃, Nd(NO₃)₃, Nd₂(SO₄)₃,Nd(CO₂CH₃)₃, Nd₂(C₂O₄)₃, EUCl₃, EuBr₃, EuI₃, Eu(NO₃)₃, Eu₂(SO₄)₃,Eu(CO₂CH₃)₃, Eu₂(C₂O₄)₃, PrCl₃, PrBr₃, PrI₃, Pr(NO₃)₃, Pr₂(SO₄)₃,Pr(CO₂CH₃)₃, Pr₂(C₂O₄)₃, SmCl₃, SmBr₃, SmI₃, Sm(NO₃)₃, Sm₂(SO₄)₃,Sm(CO₂CH₃)₃, Sm₂(C₂O₄)₃, CeCl₃, CeBr₃, CeI₃, Ce(NO₃)₃, Ce₂(SO₄)₃,Ce(CO₂CH₃)₃, Ce₂(C₂O₄)₃ or combinations thereof.

In more specific embodiments, the metal salt comprises MgCl₂, LaCl₃,ZrCl₄, WCl₄, MoCl₄, MnCl₂, MnCl₃, Mg(NO₃)₂, La(NO₃)₃, ZrOCl₂, Mn(NO₃)₂,Mn(NO₃)₃, ZrO(NO₃)₂, Zr(NO₃)₄, or combinations thereof.

In other embodiments, the metal salt comprises NdCl₃, NdBr₃, NdI₃,Nd(NO₃)₃, Nd₂(SO₄)₃, Nd(CO₂CH₃)₃, Nd₂(C₂O₄)₃, EuCl₃, EuBr₃, EuI₃,Eu(NO₃)₃, Eu₂(SO₄)₃, Eu(CO₂CH₃)₃, Eu₂(C₂O₄)₃, PrCl₃, PrBr₃, PrI₃,Pr(NO₃)₃, Pr₂(SO₄)₃, Pr(CO₂CH₃)₃, Pr₂(C₂O₄)₃ or combinations thereof.

In still other embodiments, the metal salt comprises Mg, Ca, Mg, W, La,Nd, Sm, Eu, W, Mn, Zr or mixtures thereof. The salt may be in the formof (oxy)chlorides, (oxy)nitrates or tungstates.

(c) Anion Precursor

The anions, or counter ions of the metal ions that nucleate on thetemplate, are provided in the form of an anion precursor. The anionprecursor dissociates in the solution phase and releases an anion. Thus,the anion precursor can be any stable soluble salts having the desiredanion. For instance, bases such as alkali metal hydroxides (e.g., sodiumhydroxide, lithium hydroxide, potassium hydroxides) and ammoniumhydroxide are anion precursors that provide hydroxide ions fornucleation. Alkali metal carbonates (e.g., sodium carbonate, potassiumcarbonates) and ammonium carbonate are anion precursors that providecarbonates ions for nucleation.

In certain embodiments, the anion precursor comprises one or more metalhydroxide, metal carbonate, metal bicarbonate, or metal oxalate.Preferably, the metal is an alkali or an alkaline earth metal. Thus, theanion precursor may comprise any one of alkali metal hydroxides,carbonates, bicarbonates, or oxalate; or any one of alkaline earth metalhydroxide, carbonates, bicarbonates, or oxalate.

In some specific embodiments, the one or more anion precursors comprisesLiOH, NaOH, KOH, Sr(OH)₂, Ba(OH)₂, Na₂CO₃, K₂CO₃, NaHCO₃, KHCO₃, andNR₄OH, wherein R is selected from H, and C₁-C₆ alkyl. Ammonium salts mayprovide certain advantages in that there is less possibility ofintroducing unwanted metal impurities. Accordingly, in a furtherembodiment, the anion precursor comprises ammonium hydroxide.

The dimensions of the nanowires are comparable to those of thebiological templates (e.g., phage), although they can have differentaspect ratios as longer growth can be used to increase the diameterwhile the length will increase in size at a much slower rate. Thespacing of peptides on the phage surface controls the nucleationlocation and the catalytic nanowire size based on steric hindrance. Thespecific peptide sequence information can (or may) dictate the identity,size, shape and crystalline face of the catalytic nanowire beingnucleated. To achieve the desired stochiometry between metal elements,support and dopants, multiple peptides specific for these discretematerials can be co-expressed within the same phage. Alternatively,precursor salts for the materials can be combined in the reaction at thedesired stochiometry. The techniques for phage propagation andpurification are also well established, robust and scalable.Multi-kilogram amounts of phage can be easily produced, thus assuringstraightforward scale up to large, industrial quantities.

Typical functional groups in amino acids that can be used to tailor thephage surface affinity to metal ions include: carboxylic acid (—COOH),amino (—NH₃ ⁺ or —NH₂), hydroxyl (—OH), and/or thiol (—SH) functionalgroups. Table 9 summarizes a number of exemplary phages used in thepresent invention for preparing nanowires of inorganic metal oxides.Sequences within Table 9 refer to the amino acid sequence of the pVIIIprotein (single-letter amino acid code). Underlined portions indicatethe terminal sequence which was varied to tailor the phage surfaceaffinity to metal ions. SEQ ID NO 14 represents wild type pVIII proteinwhile SEQ ID NO 15 represents wild type pVIII protein including thesignaling peptide portion (bold).

TABLE 9 SEQ ID NO Sequence  1AEEGSEDPAKAAFNSLQASATEYIGYAWAMVVVIVGATIGIKLFKKFTSKAS  2EEGSDDPAKAAFNSLQASATEYIGYAWAMVVVIVGATIGIKLFKKFTSKAS  3AEEEDPAKAAFNSLQASATEYIGYAWAMVVVIVGATIGIKLFKKFTSKAS  4EEEDPAKAAFNSLQASATEYIGYAWAMVVVIVGATIGIKLFKKFTSKAS  5AEEEEDPAKAAFNSLQASATEYIGYAWAMVVVIVGATIGIKLFKKFTSKAS  6AEEAEDPAKAAFNSLQASATEYIGYAWAMVVVIVGATIGIKLFKKFTSKAS  7EEXEDPAKAAFNSLQASATEYIGYAWAMVVVIVGATIGIKLFKKFTSKAS X = E or G  8AEDDDPAKAAFNSLQASATEYIGYAWAMVVVIVGATIGIKLFKKFTSKAS  9AVSGSSPGDDPAKAAFNSLQASATEYIGYAWAMVVVIVGATIGIKLFKKFTSKAS 10AVSGSSPDSDPAKAAFNSLQASATEYIGYAWAMVVVIVGATIGIKLFKKFTSKAS 11AGETQQAMEDPAKAAFNSLQASATEYIGYAWAMVVVIVGATIGIKLFKKFTSKAS 12AAGETQQAMDPAKAAFNSLQASATEYIGYAWAMVVVIVGATIGIKLFKKFTSKAS 13AEPGHDAVPEDPAKAAFNSLQASATEYIGYAWAMVVVIVGATIGIKLFKKFTSKAS 14AEGDDDPAKAAFNSLQASATEYIGYAWAMVVVIVGATIGIKLFKKFTSKAS 15MKKSLVLKASVAVATLVPMLSFAAEGDDDPAKAAFNSLQASATEYIGYAWAMVVVIVGATIGIKLFKKFTSKAS

3. Core/Shell Structures

In certain embodiments, nanowires can be grown on a support nanowirethat has no or a different catalytic property. FIG. 8 shows an exemplaryprocess 600 for growing a core/shell structure. Similar to FIG. 7, aphage solution is prepared (block 604), to which a first metal salt anda first anion precursor are sequentially added (blocks 610 and 620) inappropriate conditions to allow for the nucleation and growth of ananowire (M1_(m1)X1_(n1)Z_(p1)) on the phage (block 624). Thereafter, asecond metal salt and a second anion precursor are sequentially added(blocks 630 and 634), under conditions to cause the nucleation andgrowth of a coating of M2_(m2)X2_(n2)Z_(p2) on the nanowireM1_(m1)X1_(n1)Z_(p1) (block 640). Following calcinations, nanowires of acore/shell structure M1_(x1)O_(y1)/M2_(x2)O_(y2) are formed, wherein x1,y1, x2 and y2 are each independently a number from 1 to 100, and p1 andp2 are each independently a number from 0 to 100 (block 644). A furtherstep of impregnation (block 650) produces a nanowire comprising a dopantand comprising a core of M1_(x1)O_(y1) coated with a shell ofM2_(x2)O_(y2). In some embodiments, M1 is Mg, Al, Ga, Ca or Zr. Incertain embodiments of the foregoing, M1 is Mn and M2 is Mg. In otherembodiments, M1 is Mg and M2 is Mn. In other embodiments, M1 is La andM2 is Mg, Ca, Sr, Ba, Zr, Nd, Y, Yb, Eu, Sm or Ce. In other embodiments,M1 is Mg and M2 is La or Nd.

In other embodiments, M1_(x1)O_(y1) comprises La₂O₃ while in otherembodiments M2_(x2)O_(y2) comprises La₂O₃. In other embodiments of theforegoing, M1_(x1)O_(y1) or M2_(x2)O_(y2) further comprises a dopant,wherein the dopant comprises Nd, Mn, Fe, Zr, Sr, Ba, Y or combinationsthereof. Other specific combinations of core/shell nanowires are alsoenvisioned within the scope of the present disclosure.

Thus, one embodiment provides a method for preparing metal oxidenanowires in a core/shell structure, the method comprising:

(a) providing a solution that includes a plurality of biologicaltemplates;

(b) introducing a first metal ion and a first anion to the solutionunder conditions and for a time sufficient to allow for nucleation andgrowth of a first nanowire (M1_(m1)X1_(n1)Z_(p1)) on the template; and

(c) introducing a second metal ion and optionally a second anion to thesolution under conditions and for a time sufficient to allow fornucleation and growth of a second nanowire (M2_(m2)X2_(n2)Z_(p2)) on thefirst nanowire (M1_(m1)X1_(n1)Z_(p1));

(d) converting the first nanowire (M1_(m1)X1_(n1)Z_(p1)) and the secondnanowire (M2_(m2)X2_(n2)Z_(p2)) to respective metal oxide nanowires(M1_(x1)O_(y1)) and (M2_(x2)O_(y2)),

wherein:

M1 and M2 are the same or different and independently selected from ametal element;

X1 and X2 are the same or different and independently hydroxides,carbonates, bicarbonates, phosphates, hydrogenphosphates,dihydrogenphosphates, sulfates, nitrates or oxalates;

Z is O;

n1, m1, m1, m2, x1, y1, x2 and y2 are each independently a number from 1to 100; and

p1 and p2 are independently a number from 0 to 100.

In some embodiments, M1 and M2 are the same or different andindependently selected from a metal element from any of Groups 2 through7, lanthanides or actinides

In various embodiments, the biological templates are phages, as definedherein. In further embodiments, the respective metal ion is provided byadding one or more respective metal salts (as described herein) to thesolution. In other embodiments, the respective anions are provided byadding one or more respective anion precursors to the solution. Invarious embodiments, the first metal ion and the first anion can beintroduced to the solution simultaneously or sequentially in any order.Similarly, the second metal ion and optionally the second anion can beintroduced to the solution simultaneously or sequentially in any order.The first and second nanowire are typically converted to a metal oxidenanowire in a core/shell structure by calcination.

In yet another embodiment, the method further comprises doping the metaloxide nanowire in a core/shell structure with a dopant.

By varying the nucleation conditions, including the pH of the solution,relative ratio of metal salt precursors and the anion precursors,relative ratios of the precursors and the phage of the syntheticmixture, stable nanowires of diverse compositions and surface propertiescan be prepared.

In certain embodiments, the core nanowire (the first nanowire) is notcatalytically active or less so than the shell nanowire (the secondnanowire), and the core nanowire serve as an intrinsic catalytic supportfor the more active shell nanowire. For example, ZrO₂ may not have highcatalytic activity in an OCM reaction, whereas Sr²⁺doped La₂O₃ does. AZrO₂ core thus may serve as a support for the catalytic Sr²⁺doped La₂O₃shell.

In some embodiments, the present disclosure provides a nanowirecomprising a core/shell structure and comprising a ratio of effectivelength to actual length of less than one. In other embodiments, thenanowires having a core/shell structure comprise a ratio of effectivelength to actual length equal to one.

Nanowires in a core/shell arrangement may be prepared in the absence ofa biological template. For example, a nanowire comprising a first metalmay be prepared according to any of the non-template directed methodsdescribed herein. A second metal may then be nucleated or plated ontothe nanowire to form a core/shell nanowire. The first and second metalsmay be the same or different. Other methods for preparing core/shellnanowires in the absence of a biological template are also envisaged.

4. Diversity

As noted above, in some embodiments, the disclosed template-directedsynthesis provides nanowires having diverse compositions and/ormorphologies. This method combines two extremely powerful approaches,evolutionary selection and inorganic synthesis, to produce a library ofnanowire catalysts with a new level of control over materialscomposition, materials surface and crystal structure. These nanowiresprepared by biologically-templated methods take advantage of geneticengineering techniques to enable combinatorial synthesis of robust,active and selective inorganic catalytic polycrystalline nanowires. Withselection, evolution and a combinatorial library with over a hundredbillion sequence possibilities, nanowires having high specificity andproduct conversion yields in catalytic reactions are generated. Thispermits simultaneous optimization the nanowires' catalytic properties ina high-dimensional space.

In various embodiments, the synthetic parameters for nucleating andgrowing nanowires can be manipulated to create nanowires of diversecompositions and morphologies. Typical synthetic parameters include,without limitation, concentration ratios of metal ions and activefunctional groups on the phage; concentration ratios of metal and anions(e.g., hydroxide); incubation time of phage and metal salt; incubationtime of phage and anion; concentration of phage; sequence of addinganion and metal ions; pH; phage sequences; solution temperature in theincubation step and/or growth step; types of metal precursor salt; typesof anion precursor; addition rate, number of additions; the time thatlapses between the additions of the metal salt and anion precursor,including, e.g., simultaneous (zero lapse) or sequential additionsfollowed by respective incubation times for the metal salt and the anionprecursor.

Additional variable synthetic parameters include, growth time once bothmetal and anion are present in the solution; choice of solvents(although water is typically used, certain amounts of alcohol, such asmethanol, ethanol and propanol, can be mixed with water); choice and thenumber of metal salts used (e.g., both LaCl₃ and La(NO₃)₃ can be used toprovide La³⁺ ions); choice and the number of anion precursors used(e.g., both NaOH then LiOH can be used to provide the hydroxide); choiceor the number of different phage sequences used; the presence or absenceof a buffer solution; the different stages of the growing (e.g.,nanowires may be precipitated and cleaned and resuspended in a secondsolution and perform a second growth of the same material (thicker core)or different material to form a core/shell structure.

Thus, libraries of nanowires can be generated with diverse physicalproperties and characteristics such as: composition, e.g., basic metaloxides (M_(x)O_(y)), size, shape, surface morphology, exposed crystalfaces/edge density, crystallinity, dispersion, and stoichiometry andnanowire template physical characteristics including length, width,porosity and pore density. High throughput, combinatorial screeningmethods are then applied to evaluate the catalytic performancecharacteristics of the nanowires (see, e.g., FIG. 2). Based on theseresults, lead target candidates are identified. From these lead targets,further rational modifications to the synthetic designs can be made tocreate nanowires that satisfy certain catalytic performance criteria.This results in further refinement of the nanowire design and materialstructure.

Direct Synthesis of Nanowires

In some embodiments, the nanowires can be synthesized in a solutionphase in the absence of a template. Typically, a hydrothermal or sol gelapproach can be used to create straight (i.e., ratio of effective lengthto actual length equal to one) and substantially single crystallinenanowires. As an example, nanowires comprising a metal oxide can beprepared by (1) forming nanowires of a metal oxide precursor (e.g.,metal hydroxide) in a solution of a metal salt and an anion precursor;(2) isolating the nanowires of the metal oxide precursor; and (3)calcining the nanowires of the metal oxide precursor to providenanowires of a corresponding metal oxide. In other embodiments (forexample MgO nanowires), the synthesis goes through an intermediate whichcan be prepared as a nanowire and then converted into the desiredproduct while maintaining its morphology. Optionally, the nanowirescomprising a metal oxide can be doped according to methods describedherein.

In other certain embodiment, nanowires comprising a core/shell structureare prepared in the absence of a biological template. Such methods mayinclude, for example, preparing a nanowire comprising a first metal andgrowing a shell on the outersurface of this nanowire, wherein the shellcomprises a second metal. The first and second metals may be the same ordifferent.

In other aspects, a core/shell nanowire is prepared in the absence of abiological template. Such methods comprise preparing a nanowirecomprising an inner core and an outer shell, wherein the inner corecomprises a first metal, and the outer shell comprises a second metal,the method comprising:

-   -   a) preparing a first nanowire comprising the first metal; and    -   b) treating the first nanowire with a salt comprising the second        metal.

In some embodiments of the foregoing method, the method furthercomprises addition of a base to a solution obtained in step b). In yetother examples, the first metal and the second metal are different. Inyet further embodiments, the salt comprising the second metal is ahalide or a nitrate. In certain aspects it may be advantageous toperform one or more sequential additions of the salt comprising thesecond metal and a base. Such sequential additions help preventnon-selective precipitation of the second metal and favor conditionswherein the second metal nucleates on the surface of the first nanowireto form a shell of the second metal. Furthermore, the first nanowire maybe prepared by any method, for example via a template directed method(e.g., phage).

As in the template-directed synthesis, the synthetic conditions andparameters of the direct synthesis of nanowires can also be adjusted tocreate diverse compositions and surface morphologies (e.g., crystalfaces) and dopant levels. For example, variable synthetic parametersinclude: concentration ratios of metal and anions (e.g., hydroxide);reaction temperature; reaction time; sequence of adding anion and metalions; pH; types of metal precursor salt; types of anion precursor;number of additions; the time that lapses between the additions of themetal salt and anion precursor, including, e.g., simultaneous (zerolapse) or sequential additions followed by respective incubation timesfor the metal salt and the anion precursor.

In addition, the choice of solvents or surfactants may influence thecrystal growth of the nanowires, thereby generating different nanowiredimensions (including aspect ratios). For example, solvents such asethylene glycol, poly(ethylene glycol), polypropylene glycol andpoly(vinyl pyrrolidone) can serve to passivate the surface of thegrowing nanowires and facilitate a linear growth of the nanowire.

In some embodiments, nanowires can be prepared directly from thecorresponding oxide. For example, metal oxides may be treated withhalides, for example ammonium halides, to produce nanowires. Suchembodiments find particular utility in the context of lanthanide oxides,for example La₂O₃, are particularly useful since the procedure is quitesimple and economically efficient Nanowires comprising two or moremetals and/or dopants may also be prepared according to these methods.Accordingly, in some embodiments at least one of the metal compounds isan oxide of a lanthanide element. Such methods are described in moredetail in the examples.

Accordingly, in one embodiment the present disclosure provides a methodfor preparing a nanowire in the absence of a biological template, themethod comprising treating at least one metal compound with a halide. Incertain embodiments, nanowires comprising more than one type of metaland/or one or more dopants can be prepared by such methods. For example,in one embodiment the method comprises treating two or more differentmetal compounds with a halide and the nanowire comprises two or moredifferent metals. The nanowire may comprise a mixed metal oxide, metaloxyhalide, metal oxynitrate or metal sulfate.

In some other embodiments of the foregoing, the halide is in the form ofan ammonium halide. In yet other embodiments, the halide is contactedwith the metal compound in solution or in the solid state.

In certain embodiments, the method is useful for incorporation of one ormore doping elements into a nanowire. For example, the method maycomprise treating at least one metal compound with a halide in thepresence of at least one doping element, and the nanowire comprises theleast one doping element. In some aspects, the at least one dopingelement is present in the nanowire in an atomic percent ranging from 0.1to 50 at %.

Other methods for preparation of nanowires in the absence of abiological template include preparing a hydroxide gel by reaction of atleast one metal salt and a hydroxide base. For example, the method mayfurther comprise aging the gel, heating the gel or combinations thereof.In certain other embodiments, the method comprises reaction of two ormore different metal salts, and the nanowire comprises two or moredifferent metals.

Doping elements may also be incorporated by using the hydroxide gelmethod described above, further comprising addition of at least onedoping element to the hydroxide gel, and wherein the nanowire comprisesthe at least one doping element. For example, the at least one dopingelement may be present in the nanowire in an atomic percent ranging from0.1 to 50 at %.

In some embodiments, metal oxide nanowires can be prepared by mixing ametal salt solution and an anion precursor so that a gel of a metaloxide precursor is formed. This method can work for cases where thetypical morphology of the metal oxide precursor is a nanowire. The gelis thermally treated so that crystalline nanowires of the metal oxideprecursor are formed. The metal oxide precursor nanowires are convertedto metal oxide nanowires by calcination. This method can be especiallyuseful for lanthanides and group 3 elements. In some embodiments, thethermal treatment of the gel is hydrothermal (or solvothermal) attemperatures above the boiling point of the reaction mixture and atpressures above ambient pressure, in other embodiments it's done atambient pressure and at temperatures equal to or below the boiling pointof the reaction mixture. In some embodiments the thermal treatment isdone under reflux conditions at temperatures equal to the boiling pointof the mixture. In some specific embodiments the anion precursor is ahydroxide, e.g. Ammonium hydroxide, sodium hydroxide, lithium hydroxide,tetramethyl ammonium hydroxide, and the like. In some other specificembodiments the metal salt is LnCl₃ (Ln=Lanthanide), in other embodimentthe metal salt is Ln(NO₃)₃. In yet other embodiments, the metal salt isYCl₃, ScCl₃, Y(NO₃)₃, Sc(NO₃)₃. In some other embodiments, the metalprecursor solution is an aqueous solution. In other embodiments, thethermal treatment is done at T=100° C. under reflux conditions.

This method can be used to make mixed metal oxide nanowires, by mixingat least two metal salt solutions and an anion precursor so that a mixedoxide precursor gel is formed. In such cases, the first metal may be alathanide or a group 3 element, and the other metals can be from othergroups, including groups 1-14.

In some different embodiments, metal oxide nanowires can be prepared ina similar way as described above by mixing a metal salt solution and ananion precursor so that a gel of a metal hydroxide precursor is formed.This method works for cases where the typical morphology of the metalhydroxide precursor is a nanowire. The gel is treated so thatcrystalline nanowires of the metal hydroxide precursor are formed. Themetal hydroxide precursor nanowires are converted to metal hydroxidenanowires by base treatment and finally converted to metal oxidenanowires by calcination. This method may be especially applicable forgroup 2 elements, for example Mg. In some specific embodiments, the geltreatment is a thermal treatment at temperatures in the range 50-100° C.followed by hydrothermal treatment. In other embodiments, the geltreatment is an aging step. In some embodiments, the aging step takes atleast one day. In some specific embodiments, the metal salt solution isa concentrated metal chloride aqueous solution and the anion precursoris the metal oxide. In some more specific embodiments, the metal is Mg.In certain embodiments of the above, these methods can be used to makemixed metal oxide nanowires. In these embodiments, the first metal is Mgand the other metal can be any other metal of groups 1-14+Ln.

Catalytic Reactions

The present disclosure provides for the use of catalytic nanowires ascatalysts in catalytic reactions and related methods. The morphology andcomposition of the catalytic nanowires is not limited, and the nanowiresmay be prepared by any method. For example the nanowires may have a bentmorphology or a straight morphology and may have any molecularcomposition. In some embodiments, the nanowires have better catalyticproperties than a corresponding bulk catalyst (i.e., a catalyst havingthe same chemical composition as the nanowire, but prepared from bulkmaterial). In some embodiments, the nanowire having better catalyticproperties than a corresponding bulk catalyst has a ratio of effectivelength to actual length equal to one. In other embodiments, the nanowirehaving better catalytic properties than a corresponding bulk catalysthas a ratio of effective length to actual length of less than one. Inother embodiments, the nanowire having better catalytic properties thana corresponding bulk catalyst comprises one or more elements from Groups1 through 7, lanthanides or actinides.

Nanowires may be useful in any number of reactions catalyzed by aheterogeneous catalyst. Examples of reactions wherein nanowires havingcatalytic activity may be employed are disclosed in Farrauto andBartholomew, “Fundamentals of Industrial Catalytic Processes” BlackieAcademic and Professional, first edition, 1997, which is herebyincorporated in its entirety. Other non-limiting examples of reactionswherein nanowires having catalytic activity may be employed include: theoxidative coupling of methane (OCM) to ethane and ethylene; oxidativedehydrogenation (ODH) of alkanes to the corresponding alkenes, forexample oxidative dehydrogenation of ethane or propane to ethylene orpropylene, respectively; selective oxidation of alkanes, alkenes, andalkynes; oxidation of CO, dry reforming of methane, selective oxidationof aromatics; Fischer-Tropsch, hydrocarbon cracking; combustion ofhydrocarbons and the like. Reactions catalyzed by the disclosednanowires are discussed in more detail below.

The nanowires are generally useful as catalysts in methods forconverting a first carbon-containing compound (e.g., a hydrocarbon, COor CO₂) to a second carbon-containing compound. In some embodiments themethods comprise contacting a nanowire, or material comprising the same,with a gas comprising a first carbon-containing compound and an oxidantto produce a carbon-containing compound. In some embodiments, the firstcarbon-containing compound is a hydrocarbon, CO, CO₂, methane, ethane,propane, hexane, cyclohexane, octane or combinations thereof. In otherembodiments, the second carbon-containing compound is a hydrocarbon, CO,CO₂, ethane, ethylene, propane, propylene, hexane, hexane, cyclohexene,bicyclohexane, octane, octane or hexadecane. In some embodiments, theoxidant is oxygen, ozone, nitrous oxide, nitric oxide, water orcombinations thereof.

In other embodiments of the foregoing, the method for conversion of afirst carbon-containing compound to a second carbon-containing compoundis performed at a temperature below 100° C., below 200° C., below 300°C., below 400° C., below 500° C., below 600° C., below 700° C., below800° C., below 900° C. or below 1000° C. In other embodiments, themethod for conversion of a first carbon-containing compound to a secondcarbon-containing compound is performed at a pressure below 1 ATM, below2 ATM, below 5 ATM, below 10 ATM, below 25 ATM or below 50 ATM.

The catalytic reactions described herein can be performed using standardlaboratory equipment known to those of skill in the art, for example asdescribed in U.S. Pat. No. 6,350,716, which is incorporated herein inits entirety.

As noted above, the nanowires disclosed herein have better catalyticactivity than a corresponding bulk catalyst. In some embodiments, theselectivity, yield, conversion, or combinations thereof, of a reactioncatalyzed by the nanowires is better than the selectivity, yield,conversion, or combinations thereof, of the same reaction catalyzed by acorresponding bulk catalyst under the same conditions. For example, insome embodiments, the nanowire possesses a catalytic activity such thatconversion of reactant to product in a reaction catalyzed by thenanowire is greater than at least 1.1 times, greater than at least 1.25times, greater than at least 1.5 times, greater than at least 2.0 times,greater than at least 3.0 times or greater than at least 4.0 times theconversion of reactant to product in the same reaction catalyzed by acatalyst prepared from bulk material having the same chemicalcomposition as the nanowire.

In other embodiments, the nanowire possesses a catalytic activity suchthat selectivity for product in a reaction catalyzed by the nanowire isgreater than at least 1.1 times, greater than at least 1.25 times,greater than at least 1.5 times, greater than at least 2.0 times,greater than at least 3.0 times, or greater than at least 4.0 times theselectivity for product in the same reaction under the same conditionsbut catalyzed by a catalyst prepared from bulk material having the samechemical composition as the nanowire.

In yet other embodiments, the nanowire possesses a catalytic activitysuch that yield of product in a reaction catalyzed by the nanowire isgreater than at least 1.1 times, greater than at least 1.25 times,greater than at least 1.5 times, greater than at least 2.0 times,greater than at least 3.0 times, or greater than at least 4.0 times theyield of product in the same reaction under the same conditions butcatalyzed by a catalyst prepared from bulk material having the samechemical composition as the nanowire.

In certain reactions (e.g., OCM), production of unwanted oxides ofcarbon (e.g., CO and CO₂) is a problem that reduces overall yield ofdesired product and results in an environmental liability. Accordingly,in one embodiment the present disclosure addresses this problem andprovides nanowires with a catalytic activity such that the selectivityfor CO and/or CO₂ in a reaction catalyzed by the nanowires is less thanthe selectivity for CO and/or CO₂ in the same reaction under the sameconditions but catalyzed by a corresponding bulk catalyst. Accordingly,in one embodiment, the present disclosure provides a nanowire whichpossesses a catalytic activity such that selectivity for CO_(x), whereinx is 1 or 2, in a reaction catalyzed by the nanowire is less than atleast 0.9 times, less than at least 0.8 times, less than at least 0.5times, less than at least 0.2 times or less than at least 0.1 times theselectivity for CO_(X) in the same reaction under the same conditionsbut catalyzed by a catalyst prepared from bulk material having the samechemical composition as the nanowire.

In some embodiments, the absolute selectivity, yield, conversion, orcombinations thereof, of a reaction catalyzed by the nanowires disclosedherein is better than the absolute selectivity, yield, conversion, orcombinations thereof, of the same reaction under the same conditions butcatalyzed by a corresponding bulk catalyst. For example, in someembodiments the yield of product in a reaction catalyzed by thenanowires is greater than 20%, greater than 30%, greater than 50%,greater than 75%, or greater than 90%. In other embodiments, theselectivity for product in a reaction catalyzed by the nanowires isgreater than 20%, greater than 30%, greater than 50%, greater than 75%,or greater than 90%. In other embodiments, the conversion of reactant toproduct in a reaction catalyzed by the nanowires is greater than 20%,greater than 30%, greater than 50%, greater than 75%, or greater than90%.

In addition to the improved catalytic performance of the disclosednanowires, the morphology of the nanowires is expected to provide forimproved mixing properties for the nanowires compared to standardcolloidal (e.g., bulk) catalyst materials. The improved mixingproperties are expected to improve the performance of any number ofcatalytic reactions, for example, in the area of transformation of heavyhydrocarbons where transport and mixing phenomena are known to influencethe catalytic activity. In other reactions, the shape of the nanowiresis expected to provide for good blending, reduce settling, and providefor facile separation of any solid material.

In some other chemical reactions, the nanowires are useful forabsorption and/or incorporation of a reactant used in chemical looping.For example, the nanowires find utility as NO_(x) traps, in unmixedcombustion schemes, as oxygen storage materials, as CO₂ sorptionmaterials (e.g., cyclic reforming with high H₂ output) and in schemesfor conversion of water to H₂.

1. Oxidative Coupling of Methane (OCM)

As noted above, the present disclosure provides nanowires havingcatalytic activity and related approaches to nanowire design andpreparation for improving the yield, selectivity and/or conversion ofany number of catalyzed reactions, including the OCM reaction. Asmentioned above, there exists a tremendous need for catalyst technologycapable of addressing the conversion of methane into high valuechemicals (e.g., ethylene and products prepared therefrom) using adirect route that does not go through syngas. Accomplishing this taskwill dramatically impact and redefine a non-petroleum based pathway forfeedstock manufacturing and liquid fuel production yielding reductionsin GHG emissions, as well as providing new fuel sources.

Ethylene has the largest carbon footprint compared to all industrialchemical products in part due to the large total volume consumed into awide range of downstream important industrial products includingplastics, surfactants and pharmaceuticals. In 2008, worldwide ethyleneproduction exceeded 120 M metric tons while growing at a robust rate of4% per year. The United States represents the largest single producer at28% of the world capacity. Ethylene is primarily manufactured from hightemperature cracking of naphtha (e.g., oil) or ethane that is separatedfrom natural gas. The true measurement of the carbon footprint can bedifficult as it depends on factors such as the feedstock and theallocation as several products are made and separated during the sameprocess. However, some general estimates can be made based on publisheddata.

Cracking consumes a significant portion (about 65%) of the total energyused in ethylene production and the remainder is for separations usinglow temperature distillation and compression. The total tons of CO₂emission per ton of ethylene are estimated at between 0.9 to 1.2 fromethane cracking and 1 to 2 from naphtha cracking. Roughly, 60% ofethylene produced is from naphtha, 35% from ethane and 5% from otherssources (Ren, T.; Patel, M. Res. Conserv. Recycl. 53:513, 2009).Therefore, based on median averages, an estimated amount of CO₂emissions from the cracking process is 114M tons per year (based on 120Mtons produced). Separations would then account for an additional 61Mtons CO₂ per year.

Nanowires provide an alternative to the need for the energy intensivecracking step. Additionally, because of the high selectivity of thenanowires, downstream separations are dramatically simplified, ascompared to cracking which yields a wide range of hydrocarbon products.The reaction is also exothermic so it can proceed via an autothermalprocess mechanism. Overall, it is estimated that up to a potential 75%reduction in CO₂ emission compared to conventional methods could beachieved. This would equate to a reduction of one billion tons of CO₂over a ten-year period and would save over 1M barrels of oil per day.

The nanowires also permit converting ethylene into liquid fuels such asgasoline or diesel, given ethylene's high reactivity and numerouspublications demonstrating high yield reactions, in the lab setting,from ethylene to gasoline and diesel. On a life cycle basis from well towheel, recent analysis of methane to liquid (MTL) using F-T processderived gasoline and diesel fuels has shown an emission profileapproximately 20% greater to that of petroleum based production (basedon a worst case scenario) (Jaramillo, P., Griffin, M., Matthews, S.,Env. Sci. Tech 42:7559, 2008). In the model, the CO₂ contribution fromplant energy was a dominating factor at 60%. Thus, replacement of thecracking and F-T process would be expected to provide a notablereduction in net emissions, and could be produced at lower CO₂ emissionsthan petroleum based production.

Furthermore, a considerable portion of natural gas is found in regionsthat are remote from markets or pipelines. Most of this gas is flared,re-circulated back into oil reservoirs, or vented given its low economicvalue. The World Bank estimates flaring adds 400M metric tons of CO₂ tothe atmosphere each year as well as contributing to methane emissions.The nanowires of this disclosure also provide economic and environmentalincentive to stop flaring. Also, the conversion of methane to fuel hasseveral environmental advantages over petroleum-derived fuel. Naturalgas is the cleanest of all fossil fuels, and it does not contain anumber of impurities such as mercury and other heavy metals found inoil. Additionally, contaminants including sulfur are also easilyseparated from the initial natural gas stream. The resulting fuels burnmuch cleaner with no measurable toxic pollutants and provide loweremissions than conventional diesel and gasoline in use today.

In view of its wide range of applications, the nanowires of thisdisclosure can be used to not only selectively activate alkanes, butalso to activate other classes of inert unreactive bonds, such as C—F,C—Cl or C—O bonds. This has importance, for example, in the destructionof man-made environmental toxins such as CFCs, PCBs, dioxins and otherpollutants. Accordingly, while the invention is described in greaterdetail below in the context of the OCM reaction and other the otherreactions described herein, the nanowire catalysts are not in any waylimited to this particular reaction.

The selective, catalytic oxidative coupling of methane to ethylene (i.e.the OCM reaction) is shown by the following reaction (1):2CH₄+O₂→CH₂CH₂+2H₂O  (1)This reaction is exothermic (Heat of Reaction −67 kcals/mole) andusually occurs at very high temperatures (>700° C.). During thisreaction, it is believed that the methane (CH₄) is first oxidativelycoupled into ethane (C₂H₆), and subsequently the ethane (C₂H₆) isoxidatively dehydrogenated into ethylene (C₂H₄). Because of the hightemperatures used in the reaction, it has been suggested that the ethaneis produced mainly by the coupling in the gas phase of thesurface-generated methyl (CH₃) radicals. Reactive metal oxides (oxygentype ions) are apparently required for the activation of CH₄ to producethe CH₃ radicals. The yield of O₂H₄ and O₂H₆ is limited by furtherreactions in the gas phase and to some extent on the catalyst surface. Afew of the possible reactions that occur during the oxidation of methaneare shown below as reactions (2) through (8):CH₄→CH₃ radical  (2)CH₃ radical→O₂H₆  (3)CH₃ radical+2.5O₂→CO₂+1.5H₂O  (4)C₂H₆→C₂H₄+H₂  (5)C₂H₆+0.5O₂→C₂H₄+H₂O  (6)C₂H₄+3O₂→2CO₂+2H₂O  (7)CH₃ radical+C_(x)H_(y)+O₂→Higher HC's−Oxidation/CO₂+H₂O  (8)

With conventional heterogeneous catalysts and reactor systems, thereported performance is generally limited to <25% CH₄ conversion at <80%combined O₂ selectivity, with the performance characteristics of highselectivity at low conversion, or the low selectivity at highconversion. In contrast, the nanowires of this disclosure are highlyactive and can optionally operate at a much lower temperature. In oneembodiment, the nanowires disclosed herein enable efficient conversionof methane to ethylene in the OCM reaction at temperatures less thanwhen the corresponding bulk material is used as a catalyst. For example,in one embodiment, the nanowires disclosed herein enable efficientconversion (i.e., high yield, conversion, and/or selectivity) of methaneto ethylene at temperatures of less than 900° C., less than 800° C.,less than 700° C., less than 600° C., or less than 500° C. In otherembodiments, the use of staged oxygen addition, designed heatmanagement, rapid quench and/or advanced separations may also beemployed.

Typically, the OCM reaction is run in a mixture of oxygen and nitrogenor other inert gas. Such gasses are expensive and increase the overallproduction costs associated with preparation of ethylene or ethane frommethane. However, the present inventors have now discovered that suchexpensive gases are not required and high yield, conversion,selectivity, etc. can be obtained when air is used as the gas mixtureinstead of pre-packaged and purified sources of oxygen and other gases.Accordingly, in one embodiment the disclosure provides a method forperforming the OCM reaction in air. In these embodiments, the catalyst

Accordingly, in one embodiment a stable, very active, high surface area,multifunctional nanowire catalyst is disclosed having active sites thatare isolated and precisely engineered with the catalytically activemetal centers/sites in the desired proximity (see, e.g., FIG. 1).

The exothermic heats of reaction (free energy) follows the order ofreactions depicted above and, because of the proximity of the activesites, will mechanistically favor ethylene formation while minimizingcomplete oxidation reactions that form CO and CO₂. Representativenanowire compositions useful for the OCM reaction include, but are notlimited to: highly basic oxides selected from the early members of theLanthanide oxide series; Group 1 or 2 ions supported on basic oxides,such as Li/MgO, Ba/MgO and Sr/La₂O₃; and single or mixed transitionmetal oxides, such as VO_(x) and Re/Ru that may also contain Group 1ions. Other nanowire compositions useful for the OCM reaction compriseany of the compositions disclosed herein, for example MgO, La₂O₃,Na₂WO₄, Mn₂O₃, Mn₃O₄, Mg₆MnO₈, Zr₂Mo₂O₈, NaMnO₄, Mn₂O₃/Na₂WO₄,Mn₃O₄/Na₂WO₄ or Na/MnO₄/MgO, Mn/WO4, Nd₂O₃, Sm₂O₃, Eu₂O₃ or combinationsthereof. Activating promoters (i.e., dopants), such as chlorides,nitrates and sulfates, or any of the dopants described above may also beemployed.

As noted above, the OCM reaction employing known bulk catalysts suffersfrom poor yield, selectivity, or conversion. In contrast to acorresponding bulk catalyst, Applicants have found that certainnanowires, for example the exemplary nanowires disclosed herein, possesa catalytic activity in the OCM reaction such that the yield,selectivity, and/or conversion is better than when the OCM reaction iscatalyzed by a corresponding bulk catalyst. In one embodiment, thedisclosure provides a nanowire having a catalytic activity such that theconversion of methane to ethylene in the oxidative coupling of methanereaction is greater than at least 1.1 times, 1.25 times, 1.50 times, 2.0times, 3.0 times, or 4.0 times the conversion of methane to ethylenecompared to the same reaction under the same conditions but performedwith a catalyst prepared from bulk material having the same chemicalcomposition as the nanowire. In other embodiments, the conversion ofmethane to ethylene in an OCM reaction catalyzed by the nanowire isgreater than 10%, greater than 20%, greater than 30%, greater than 50%,greater than 75%, or greater than 90%.

In another embodiment, the disclosure provides a nanowire having acatalytic activity such that the yield of ethylene in the oxidativecoupling of methane reaction is greater than at least 1.1 times, 1.25times, 1.50 times, 2.0 times, 3.0 times, or 4.0 times the yield ofethylene compared to the same reaction under the same conditions butperformed with a catalyst prepared from bulk material having the samechemical composition as the nanowire. In some embodiments the yield ofethylene in an OCM reaction catalyzed by the nanowire is greater than10%, greater than 20%, greater than 30%, greater than 50%, greater than75%, or greater than 90%.

In another embodiment, the disclosure provides a nanowire having acatalytic activity in the OCM reaction such that the nanowire has thesame catalytic activity, but at a lower temperature, compared a catalystprepared from bulk material having the same chemical composition as thenanowire. In some embodiments the catalytic activity of the nanowires inthe OCM reaction is the same as the catalytic activity of a catalystprepared from bulk material having the same chemical composition as thenanowire, but at a temperature of at least 20° C. less. In someembodiments the catalytic activity of the nanowires in the OCM reactionis the same as the catalytic activity of a catalyst prepared from bulkmaterial having the same chemical composition as the nanowire, but at atemperature of at least 50° C. less. In some embodiments the catalyticactivity of the nanowires in the OCM reaction is the same as thecatalytic activity of a catalyst prepared from bulk material having thesame chemical composition as the nanowire, but at a temperature of atleast 100° C. less. In some embodiments the catalytic activity of thenanowires in the OCM reaction is the same as the catalytic activity of acatalyst prepared from bulk material having the same chemicalcomposition as the nanowire, but at a temperature of at least 200° C.less.

In another embodiment, the disclosure provides a nanowire having acatalytic activity such that the selectivity for CO or CO₂ in theoxidative coupling of methane reaction is less than at least 0.9 times,0.8 times, 0.5 times, 0.2 times, or 0.1 times the selectivity for CO orCO₂ compared to the same reaction under the same conditions butperformed with a catalyst prepared from bulk material having the samechemical composition as the nanowire.

In some other embodiments, a method for converting methane into ethylenecomprising use of catalyst mixture comprising two or more catalysts isprovided. For example, the catalyst mixture may be a mixture of acatalyst having good OCM activity and a catalyst having good ODHactivity. Such catalyst mixture are described in more detail above.

2. Oxidative Dehydrogenation

Worldwide demand for alkenes, especially ethylene and propylene, ishigh. The main sources for alkenes include steam cracking,fluid-catalytic-cracking and catalytic dehydrogenation. The currentindustrial processes for producing alkenes, including ethylene andpropylene, suffer from some of the same disadvantages described abovefor the OCM reaction. Accordingly, a process for the preparation ofalkenes which is more energy efficient and has higher yield,selectivity, and conversion than current processes is needed. Applicantshave now found that nanowires, for example the exemplary nanowiresdisclosed herein, fulfill this need and provide related advantages.

In one embodiment, the disclosed nanowires are useful as catalysts forthe oxidative dehydrogenation (ODH) of hydrocarbons (e.g. alkanes,alkenes, and alkynes). For example, in one embodiment the nanowires areuseful as catalysts in an ODH reaction for the conversion of ethane orpropane to ethylene or propylene, respectively. Reaction scheme (9)depicts the oxidative dehydrogenation of hydrocarbons:C_(x)H_(y)+½O₂→C_(x)H_(y-2)+H₂O  (9)

Representative catalysts useful for the ODH reaction include, but arenot limited to nanowires comprising Zr, V, Mo, Ba, Nd, Ce, Ti, Mg, Nb,La, Sr, Sm, Cr, W, Y or Ca or oxides or combinations thereof. Activatingpromoters (i.e. dopants) comprising P, K, Ca, Ni, Cr, Nb, Mg, Au, Zn, orMo, or combinations thereof, may also be employed.

As noted above, improvements to the yield, selectivity, and/orconversion in the ODH reaction employing bulk catalysts are needed.Accordingly, in one embodiment, the present disclosure provides ananowire which posses a catalytic activity in the ODH reaction such thatthe yield, selectivity, and/or conversion is better than when the ODHreaction is catalyzed by a corresponding bulk catalyst. In oneembodiment, the disclosure provides a nanowire having a catalyticactivity such that the conversion of hydrocarbon to alkene in the ODHreaction is greater than at least 1.1 times, 1.25 times, 1.50 times, 2.0times, 3.0 times, or 4.0 times the conversion of methane to ethylenecompared to the same reaction under the same conditions but performedwith a catalyst prepared from bulk material having the same chemicalcomposition as the nanowire. In other embodiments, the conversion ofhydrocarbon to alkene in an ODH reaction catalyzed by the nanowire isgreater than 10%, greater than 20%, greater than 30%, greater than 50%,greater than 75%, or greater than 90%.

In another embodiment, the disclosure provides a nanowire having acatalytic activity such that the yield of alkene in an ODH reaction isgreater than at least 1.1 times, 1.25 times, 1.50 times, 2.0 times, 3.0times, or 4.0 times the yield of ethylene compared to the same reactionunder the same conditions but performed with a catalyst prepared frombulk material having the same chemical composition as the nanowire. Insome embodiments the yield of alkene in an ODH reaction catalyzed by thenanowire is greater than 10%, greater than 20%, greater than 30%,greater than 50%, greater than 75%, or greater than 90%.

In another embodiment, the disclosure provides a nanowire having acatalytic activity in the ODH reaction such that the nanowire has thesame catalytic activity, but at a lower temperature, compared a catalystprepared from bulk material having the same chemical composition as thenanowire. In some embodiments the catalytic activity of the nanowires inthe ODH reaction is the same as the catalytic activity of a catalystprepared from bulk material having the same chemical composition as thenanowire, but at a temperature of at least 20° C. less. In someembodiments the catalytic activity of the nanowires in the ODH reactionis the same as the catalytic activity of a catalyst prepared from bulkmaterial having the same chemical composition as the nanowire, but at atemperature of at least 50° C. less. In some embodiments the catalyticactivity of the nanowires in the ODH reaction is the same as thecatalytic activity of a catalyst prepared from bulk material having thesame chemical composition as the nanowire, but at a temperature of atleast 100° C. less. In some embodiments the catalytic activity of thenanowires in the ODH reaction is the same as the catalytic activity of acatalyst prepared from bulk material having the same chemicalcomposition as the nanowire, but at a temperature of at least 200° C.less.

In another embodiment, the disclosure provides a nanowire having acatalytic activity such that the selectivity for alkenes in an ODHreaction is greater than at least 1.1 times, 1.25 times, 1.50 times, 2.0times, 3.0 times, or 4.0 times the selectivity for ethylene compared tothe same reaction under the same conditions but performed with acatalyst prepared from bulk material having the same chemicalcomposition as the nanowire. In other embodiments, the selectivity foralkenes in an ODH reaction catalyzed by the nanowire is greater than10%, greater than 20%, greater than 30%, greater than 50%, greater than75%, or greater than 90%.

In another embodiment, the disclosure provides a nanowire having acatalytic activity such that the selectivity for CO or CO₂ in an ODHreaction is less than at least 0.9 times, 0.8 times, 0.5 times, 0.2times, or 0.1 times the selectivity for CO or CO₂ compared to the samereaction under the same conditions but performed with a catalystprepared from bulk material having the same chemical composition as thenanowire.

In one embodiment, the nanowires disclosed herein enable efficientconversion of hydrocarbon to alkene in the ODH reaction at temperaturesless than when the corresponding bulk material is used as a catalyst.For example, in one embodiment, the nanowires disclosed herein enableefficient conversion (i.e. high yield, conversion, and/or selectivity)of hydrocarbon to alkene at temperatures of less than 800° C., less than700° C., less than 600° C., less than 500° C., less than 400° C., orless than 300° C.

3. Carbon Dioxide Reforming of Methane

Carbon dioxide reforming (CDR) of methane is an attractive process forconverting CO₂ in process streams or naturally occurring sources intothe valuable chemical product, syngas (a mixture of hydrogen and carbonmonoxide). Syngas can then be manufactured into a wide range ofhydrocarbon products through processes such as the Fischer-Tropschsynthesis (discussed below) to form liquid fuels including methanol,ethanol, diesel, and gasoline. The result is a powerful technique to notonly remove CO₂ emissions but also create a new alternative source forfuels that are not derived from petroleum crude oil. The CDR reactionwith methane is exemplified in reaction scheme (10).CO₂+CH₄→2CO+2H₂  (10)

Unfortunately, no established industrial technology for CDR exists todayin spite of its tremendous potential value. While not wishing to bebound by theory, it is thought that the primary problem with CDR is dueto side-reactions from catalyst deactivation induced by carbondeposition via the Boudouard reaction (reaction scheme (11)) and/ormethane cracking (reaction scheme (12)) resulting from the hightemperature reaction conditions. The occurrence of the coking effect isintimately related to the complex reaction mechanism, and the associatedreaction kinetics of the catalysts employed in the reaction.2CO→C+CO₂  (11)CH₄→C+2H₂  (12)

While not wishing to be bound by theory, the CDR reaction is thought toproceed through a multistep surface reaction mechanism. FIG. 9schematically depicts a CDR reaction 700, in which activation anddissociation of CH₄ occurs on the metal catalyst surface 710 to formintermediate “M-C”. At the same time, absorption and activation of CO₂takes place at the oxide support surface 720 to provide intermediate“S—CO₂”, since the carbon in a CO₂ molecule as a Lewis acid tends toreact with the Lewis base center of an oxide. The final step is thereaction between the M-C species and the activated S—CO₂ to form CO.

In one embodiment, the present disclosure provides nanowires, forexample the exemplary nanowires disclosed herein, which are useful ascatalysts for the carbon dioxide reforming of methane. For example, inone embodiment the nanowires are useful as catalysts in a CDR reactionfor the production of syn gas.

Improvements to the yield, selectivity, and/or conversion in the CDRreaction employing bulk catalysts are needed. Accordingly, in oneembodiment, the nanowires posses a catalytic activity in the CDRreaction such that the yield, selectivity, and/or conversion is betterthan when the CDR reaction is catalyzed by a corresponding bulkcatalyst. In one embodiment, the disclosure provides a nanowire having acatalytic activity such that the conversion of CO₂ to CO in the CDRreaction is greater than at least 1.1 times, 1.25 times, 1.50 times, 2.0times, 3.0 times, or 4.0 times the conversion of CO₂ to CO compared tothe same reaction under the same conditions but performed with acatalyst prepared from bulk material having the same chemicalcomposition as the nanowire. In other embodiments, the conversion of CO₂to CO in a CDR reaction catalyzed by the nanowire is greater than 10%,greater than 20%, greater than 30%, greater than 50%, greater than 75%,or greater than 90%.

In another embodiment, the disclosure provides a nanowire having acatalytic activity such that the yield of CO in a CDR reaction isgreater than at least 1.1 times, 1.25 times, 1.50 times, 2.0 times, 3.0times, or 4.0 times the yield of CO compared to the same reaction underthe same conditions but performed with a catalyst prepared from bulkmaterial having the same chemical composition as the nanowire. In someembodiments the yield of CO in a CDR reaction catalyzed by the nanowireis greater than 10%, greater than 20%, greater than 30%, greater than50%, greater than 75%, or greater than 90%.

In another embodiment, the disclosure provides a nanowire having acatalytic activity in a CDR reaction such that the nanowire has the samecatalytic activity, but at a lower temperature, compared a catalystprepared from bulk material having the same chemical composition as thenanowire. In some embodiments the catalytic activity of the nanowires ina CDR reaction is the same as the catalytic activity of a catalystprepared from bulk material having the same chemical composition as thenanowire, but at a temperature of at least 20° C. less. In someembodiments the catalytic activity of the nanowires in a CDR reaction isthe same as the catalytic activity of a catalyst prepared from bulkmaterial having the same chemical composition as the nanowire, but at atemperature of at least 50° C. less. In some embodiments the catalyticactivity of the nanowires in a CDR reaction is the same as the catalyticactivity of a catalyst prepared from bulk material having the samechemical composition as the nanowire, but at a temperature of at least100° C. less. In some embodiments the catalytic activity of thenanowires in a CDR reaction is the same as the catalytic activity of acatalyst prepared from bulk material having the same chemicalcomposition as the nanowire, but at a temperature of at least 200° C.less.

In another embodiment, the disclosure provides a nanowire having acatalytic activity such that the selectivity for CO in a CDR reaction isgreater than at least 1.1 times, 1.25 times, 1.50 times, 2.0 times, 3.0times, or 4.0 times the selectivity for CO compared to the same reactionunder the same conditions but performed with a catalyst prepared frombulk material having the same chemical composition as the nanowire. Inother embodiments, the selectivity for CO in a CDR reaction catalyzed bythe nanowire is greater than 10%, greater than 20%, greater than 30%,greater than 50%, greater than 75%, or greater than 90%.

In one embodiment, the nanowires disclosed herein enable efficientconversion of CO₂ to CO in the CDR reaction at temperatures less thanwhen the corresponding bulk material is used as a catalyst. For example,in one embodiment, the nanowires enable efficient conversion (i.e., highyield, conversion, and/or selectivity) of CO₂ to CO at temperatures ofless than 900° C., less than 800° C., less than 700° C., less than 600°C., or less than 500° C.

4. Fischer-Tropsch Synthesis

Fischer-Tropsch synthesis (FTS) is a valuable process for convertingsynthesis gas (i.e., CO and H₂) into valuable hydrocarbon fuels, forexample, light alkenes, gasoline, diesel fuel, etc. FTS has thepotential to reduce the current reliance on the petroleum reserve andtake advantage of the abundance of coal and natural gas reserves.Current FTS processes suffer from poor yield, selectivity, conversion,catalyst deactivation, poor thermal efficiency and other relateddisadvantages. Production of alkanes via FTS is shown in reaction scheme(13), wherein n is an integer.CO+2H₂→(1/n)(C_(n)H_(2n))+H₂O  (13)

In one embodiment, nanowires are provided which are useful as catalystsin FTS processes. For example, in one embodiment the nanowires areuseful as catalysts in a FTS process for the production of alkanes.

Improvements to the yield, selectivity, and/or conversion in FTSprocesses employing bulk catalysts are needed. Accordingly, in oneembodiment, the nanowires posses a catalytic activity in an FTS processsuch that the yield, selectivity, and/or conversion is better than whenthe FTS process is catalyzed by a corresponding bulk catalyst. In oneembodiment, the disclosure provides a nanowire having a catalyticactivity such that the conversion of CO to alkane in an FTS process isgreater than at least 1.1 times, 1.25 times, 1.50 times, 2.0 times, 3.0times, or 4.0 times the conversion of CO to alkane compared to the samereaction under the same conditions but performed with a catalystprepared from bulk material having the same chemical composition as thenanowire. In other embodiments, the conversion of CO to alkane in an FTSprocess catalyzed by the nanowire is greater than 10%, greater than 20%,greater than 30%, greater than 50%, greater than 75%, or greater than90%.

In another embodiment, the disclosure provides a nanowire having acatalytic activity in an FTS process such that the nanowire has the samecatalytic activity, but at a lower temperature, compared a catalystprepared from bulk material having the same chemical composition as thenanowire. In some embodiments the catalytic activity of the nanowires inan FTS process is the same as the catalytic activity of a catalystprepared from bulk material having the same chemical composition as thenanowire, but at a temperature of at least 20° C. less. In someembodiments the catalytic activity of the nanowires in an FTS process isthe same as the catalytic activity of a catalyst prepared from bulkmaterial having the same chemical composition as the nanowire, but at atemperature of at least 50° C. less. In some embodiments the catalyticactivity of the nanowires in an FTS process is the same as the catalyticactivity of a catalyst prepared from bulk material having the samechemical composition as the nanowire, but at a temperature of at least100° C. less. In some embodiments the catalytic activity of thenanowires in an FTS process is the same as the catalytic activity of acatalyst prepared from bulk material having the same chemicalcomposition as the nanowire, but at a temperature of at least 200° C.less.

In another embodiment, the disclosure provides a nanowire having acatalytic activity such that the yield of alkane in a FTS process isgreater than at least 1.1 times, 1.25 times, 1.50 times, 2.0 times, 3.0times, or 4.0 times the yield of alkane compared to the same reactionunder the same conditions but performed with a catalyst prepared frombulk material having the same chemical composition as the nanowire. Insome embodiments the yield of alkane in an FTS process catalyzed by thenanowire is greater than 10%, greater than 20%, greater than 30%,greater than 50%, greater than 75%, or greater than 90%.

In another embodiment, the disclosure provides a nanowire having acatalytic activity such that the selectivity for alkanes in an FTSprocess is greater than at least 1.1 times, 1.25 times, 1.50 times, 2.0times, 3.0 times, or 4.0 times the selectivity for alkanes compared tothe same reaction under the same conditions but performed with acatalyst prepared from bulk material having the same chemicalcomposition as the nanowire. In other embodiments, the selectivity foralkanes in an FTS process catalyzed by the nanowire is greater than 10%,greater than 20%, greater than 30%, greater than 50%, greater than 75%,or greater than 90%.

In one embodiment, the nanowires disclosed herein enable efficientconversion of CO to alkanes in a CDR process at temperatures less thanwhen the corresponding bulk material is used as a catalyst. For example,in one embodiment, the nanowires enable efficient conversion (i.e., highyield, conversion, and/or selectivity) of CO to alkanes at temperaturesof less than 400° C., less than 300° C., less than 250° C., less than200° C., less the 150° C., less than 100° C. or less than 50° C.

5. Oxidation of CO

Carbon monoxide (CO) is a toxic gas and can convert hemoglobin tocarboxyhemoglobin resulting in asphyxiation. Dangerous levels of CO canbe reduced by oxidation of C0 to CO2 as shown in reaction scheme 14:CO+½O₂→CO₂  (14)

Catalysts for the conversion of CO into CO₂ have been developed butimprovements to the known catalysts are needed. Accordingly in oneembodiment, the present disclosure provides nanowires useful ascatalysts for the oxidation of CO to CO₂.

In one embodiment, the nanowires posses a catalytic activity in aprocess for the conversion of CO into CO₂ such that the yield,selectivity, and/or conversion is better than when the oxidation of COinto CO₂ is catalyzed by a corresponding bulk catalyst. In oneembodiment, the disclosure provides a nanowire having a catalyticactivity such that the conversion of CO to CO₂ is greater than at least1.1 times, 1.25 times, 1.50 times, 2.0 times, 3.0 times, or 4.0 timesthe conversion of CO to CO₂ compared to the same reaction under the sameconditions but performed with a catalyst prepared from bulk material andhaving the same chemical composition as the nanowire. In otherembodiments, the conversion of CO to CO₂ catalyzed by the nanowire isgreater than 10%, greater than 20%, greater than 30%, greater than 50%,greater than 75%, or greater than 90%.

In another embodiment, the disclosure provides a nanowire having acatalytic activity such that the yield of CO₂ from the oxidation of COis greater than at least 1.1 times, 1.25 times, 1.50 times, 2.0 times,3.0 times, or 4.0 times the yield of CO₂ compared to the same reactionunder the same conditions but performed with a catalyst prepared frombulk material having the same chemical composition as the nanowire. Insome embodiments the yield of CO₂ from the oxidation of CO catalyzed bythe nanowire is greater than 10%, greater than 20%, greater than 30%,greater than 50%, greater than 75%, or greater than 90%.

In another embodiment, the disclosure provides a nanowire having acatalytic activity in an oxidation of CO reaction such that the nanowirehas the same catalytic activity, but at a lower temperature, compared acatalyst prepared from bulk material having the same chemicalcomposition as the nanowire. In some embodiments the catalytic activityof the nanowires in an oxidation of CO reaction is the same as thecatalytic activity of a catalyst prepared from bulk material having thesame chemical composition as the nanowire, but at a temperature of atleast 20° C. less. In some embodiments the catalytic activity of thenanowires in an oxidation of CO reaction is the same as the catalyticactivity of a catalyst prepared from bulk material having the samechemical composition as the nanowire, but at a temperature of at least50° C. less. In some embodiments the catalytic activity of the nanowiresin an oxidation of CO reaction is the same as the catalytic activity ofa catalyst prepared from bulk material having the same chemicalcomposition as the nanowire, but at a temperature of at least 100° C.less. In some embodiments the catalytic activity of the nanowires in anoxidation of CO reaction is the same as the catalytic activity of acatalyst prepared from bulk material having the same chemicalcomposition as the nanowire, but at a temperature of at least 200° C.less.

In another embodiment, the disclosure provides a nanowire having acatalytic activity such that the selectivity for CO₂ in the oxidation ofCO is greater than at least 1.1 times, 1.25 times, 1.50 times, 2.0times, 3.0 times, or 4.0 times the selectivity for CO₂ compared to thesame reaction under the same conditions but performed with a catalystprepared from bulk material having the same chemical composition as thenanowire. In other embodiments, the selectivity for CO₂ in the oxidationof CO catalyzed by the nanowire is greater than 10%, greater than 20%,greater than 30%, greater than 50%, greater than 75%, or greater than90%.

In one embodiment, the nanowires disclosed herein enable efficientconversion of CO to CO₂ at temperatures less than when the correspondingbulk material is used as a catalyst. For example, in one embodiment, thenanowires enable efficient conversion (i.e., high yield, conversion,and/or selectivity) of CO to CO₂ at temperatures of less than 500° C.,less than 400° C., less than 300° C., less than 200° C., less than 100°C., less than 50° C. or less than 20° C.

Although various reactions have been described in detail, the disclosednanowires are useful as catalysts in a variety of other reactions. Ingeneral, the disclosed nanowires find utility in any reaction utilizinga heterogeneous catalyst and have a catalytic activity such that theyield, conversion, and/or selectivity in reaction catalyzed by thenanowires is better than the yield, conversion and/or selectivity in thesame reaction catalyzed by a corresponding bulk catalyst.

6. Combustion of Hydrocarbons

In another embodiment, the present disclosure provides a nanowire havingcatalytic activity in a reaction for the catalyzed combustion ofhydrocarbons. Such catalytic reactions find utility in catalyticconverters for automobiles, for example by sooth reduction on dieselengines by catalytically burn unused hydrocarbons emitted from theengine when it's running “cold” and thus the engine efficiency inburning hydrocarbons is not very good. When running “cold”, the exhaustsof a diesel engine are quite low, thus a low temperature, such as thedisclosed nanowires, catalyst is needed to efficiently eliminate allunburned hydrocarbons.

In contrast to a corresponding bulk catalyst, Applicants have found thatcertain nanowires, for example the exemplary nanowires disclosed herein,posses a catalytic activity in the combustion of hydrocarbons such thatthe yield, selectivity, and/or conversion is better than when thecombustion of hydrocarbons is catalyzed by a corresponding bulkcatalyst. In one embodiment, the disclosure provides a nanowire having acatalytic activity such that the combustion of hydrocarbons is greaterthan at least 1.1 times, 1.25 times, 1.50 times, 2.0 times, 3.0 times,or 4.0 times the combustion of hydrocarbons compared to the samereaction under the same conditions but performed with a catalystprepared from bulk material having the same chemical composition as thenanowire. In other embodiments, the total combustion of hydrocarbonscatalyzed by the nanowire is greater than 10%, greater than 20%, greaterthan 30%, greater than 50%, greater than 75%, or greater than 90%.

In another embodiment, the disclosure provides a nanowire having acatalytic activity such that the yield of combusted hydrocarbon productsis greater than at least 1.1 times, 1.25 times, 1.50 times, 2.0 times,3.0 times, or 4.0 times the yield of combusted hydrocarbon productscompared to the same reaction under the same conditions but performedwith a catalyst prepared from bulk material having the same chemicalcomposition as the nanowire. In some embodiments the yield of combustedhydrocarbon products in a reaction catalyzed by the nanowire is greaterthan 10%, greater than 20%, greater than 30%, greater than 50%, greaterthan 75%, or greater than 90%.

In another embodiment, the disclosure provides a nanowire having acatalytic activity in the combustion of hydrocarbons such that thenanowire has the same catalytic activity, but at a lower temperature,compared a catalyst prepared from bulk material having the same chemicalcomposition as the nanowire. In some embodiments the catalytic activityof the nanowires in the combustion of hydrocarbons is the same as thecatalytic activity of a catalyst prepared from bulk material having thesame chemical composition as the nanowire, but at a temperature of atleast 20° C. less. In some embodiments the catalytic activity of thenanowires in the combustion of hydrocarbons is the same as the catalyticactivity of a catalyst prepared from bulk material having the samechemical composition as the nanowire, but at a temperature of at least50° C. less. In some embodiments the catalytic activity of the nanowiresin the combustion of hydrocarbons is the same as the catalytic activityof a catalyst prepared from bulk material having the same chemicalcomposition as the nanowire, but at a temperature of at least 100° C.less. In some embodiments the catalytic activity of the nanowires in thecombustion of hydrocarbons is the same as the catalytic activity of acatalyst prepared from bulk material having the same chemicalcomposition as the nanowire, but at a temperature of at least 200° C.less.

7. Evaluation of Catalytic Properties

To evaluate the catalytic properties of the nanowires in a givenreaction, for example those reactions discussed above, various methodscan be employed to collect and process data including measurements ofthe kinetics and amounts of reactants consumed and the products formed.In addition to allowing for the evaluation of the catalyticperformances, the data can also aid in designing large scale reactors,experimentally validating models and optimizing the catalytic process.

One exemplary methodology for collecting and processing data is depictedin FIG. 10. Three main steps are involved. The first step (block 750)comprises the selection of a reaction and catalyst. This influences thechoice of reactor and how it is operated, including batch, flow, etc.(block 754). Thereafter, the data of the reaction are compiled andanalyzed (block 760) to provide insights to the mechanism, rates andprocess optimization of the catalytic reaction. In addition, the dataprovide useful feed backs for further design modifications of thereaction conditions. Additional methods for evaluating catalyticperformance in the laboratory and industrial settings are described in,for example, Bartholomew, C. H. et al. Fundamentals of IndustrialCatalytic Processes, Wiley-AIChE; 2Ed (1998).

As an example, in a laboratory setting, an Altamira Benchcat 200 can beemployed using a 4 mm ID diameter quartz tube with a 0.5 mm ID capillarydownstream. Quartz tubes with 2 mm or 6 mm ID can also be used.Nanowires are tested in a number of different dilutions and amounts. Insome embodiments, the range of testing is between 10 and 300 mg. In someembodiments, the nanowires are diluted with a non-reactive diluent. Thisdiluent can be quartz (SiO₂) or other inorganic materials which areknown to be inert in the reaction condition. The purpose of the diluentis to minimize hot spots and provide an appropriate loading into thereactor. In addition, the catalyst can be blended with lesscatalytically active components as described in more detail above.

In a typical procedure, 100 mg is the total charge of nanowire,optionally including diluent. On either side of the nanowires a smallplug of glass wool is loaded to keep the nanowires in place. Athermocouple is placed on the inlet side of the nanowire bed into theglass wool to get the temperature in the reaction zone. Anotherthermocouple can be placed on the downstream end of the nanowire bedinto the catalyst bed itself to measure the exotherms, if any.

When blending the pure nanowire with diluent, the following exemplaryprocedure may be used: x (usually 10-50) mg of the catalyst (either bulkor test nanowire catalyst) is blended with (100-x) mg of quartz (SiO₂).Thereafter, about 2 ml of ethanol or water is added to form a slurrymixture, which is then sonicated for about 10 minutes. The slurry isthen dried in an oven at about 100-140° C. for 2 hours to removesolvent. The resulting solid mixture is then scraped out and loaded intothe reactor between the plugs of quartz wool.

Once loaded into the reactor, the reactor is inserted into the Altamirainstrument and furnace and then a temperature and flow program isstarted. In some embodiment, the total flow is 50 to 100 sccm of gasesbut this can be varied and programmed with time. In one embodiment, thetemperatures range from 450° C. to 900° C. The reactant gases compriseair or oxygen (diluted with nitrogen or argon) and methane in the caseof the OCM reaction and gas mixtures comprising ethane and/or propanewith oxygen for oxidative dehydrogenation (ODH) reactions. Other gasmixtures can be used for other reactions.

The primary analysis of these oxidation catalysis runs is the GasChromatography (GC) analysis of the feed and effluent gases. From theseanalyses, the conversion of the oxygen and alkane feed gases can easilybe attained and estimates of yields and selectivities of the productsand by-products can be determined.

The GC method developed for these experiments employs 4 columns and 2detectors and a complex valve switching system to optimize the analysis.Specifically, a flame ionization detector (FID) is used for the analysisof the hydrocarbons only. It is a highly sensitive detector thatproduces accurate and repeatable analysis of methane, ethane, ethylene,propane, propylene and all other simple alkanes and alkenes up to fivecarbons in length and down to ppm levels.

There are two columns in series to perform this analysis, the first is astripper column (alumina) which traps polar materials (including thewater by-product and any oxygenates generated) until back-flushed laterin the cycle. The second column associated with the FID is a capillaryalumina column known as a PLOT column which performs the actualseparation of the light hydrocarbons. The water and oxygenates are notanalyzed in this method.

For the analysis of the light non-hydrocarbon gases, a ThermalConductivity Detector (TCD) may be employed which also employees twocolumns to accomplish its analysis. The target molecules for thisanalysis are CO₂, ethylene, ethane, hydrogen, oxygen, nitrogen, methaneand CO. The two columns used here are a porous polymer column known asthe Hayes Sep N which performs some of the separation for the CO₂,ethylene and ethane. The second column is a molecular sieve column whichuses size differentiation to perform the separation. It is responsiblefor the separation of H₂, O₂, N₂, methane and CO.

There is a sophisticated and timing sensitive switching between thesetwo columns in the method. In the first 2 minutes or so, the two columnsare operating in series but at about 2 minutes, the molecular sievecolumn is by-passed and the separation of the first 3 components iscompleted. At about 5-7 minutes, the columns are then placed back inseries and the light gases come off of the sieve according to theirmolecular size.

The end result is an accurate analysis of all of the aforementionedcomponents from these fixed-bed, gas phase reactions. Analysis of otherreactions and gases not specifically described above can be performed ina similar manner.

8. Downstream Products

As noted above, in one embodiment the present disclosure is directed tonanowires useful as catalysts in reactions for the preparation of anumber of valuable hydrocarbon compounds. For example, in one embodimentthe nanowires are useful as catalysts for the preparation of ethylenefrom methane via the OCM reaction. In another embodiment, the nanowiresare useful as catalysts for the preparation of ethylene or propylene viaoxidative dehydrogenation of ethane or propane, respectively. Ethyleneand propylene are valuable compounds which can be converted into avariety of consumer products. For example, as shown in FIG. 11, ethylenecan be converted into many various compounds including low densitypolyethylene, high density polyethylene, ethylene dichloride, ethyleneoxide, ethylbenzene, linear alcohols, vinyl acetate, alkanes, alphaolefins, various hydrocarbon-based fuels, ethanol and the like. Thesecompounds can then be further processed using methods well known to oneof ordinary skill in the art to obtain other valuable chemicals andconsumer products (e.g. the downstream products shown in FIG. 11).Propylene can be analogously converted into various compounds andconsumer goods including polypropylenes, propylene oxides, propanol, andthe like.

Accordingly, in one embodiment the disclosure provides a method ofpreparing the downstream products of ethylene noted in FIG. 11. Themethod comprises converting ethylene into a downstream product ofethylene, wherein the ethylene has been prepared via a catalyticreaction employing a nanowire, for example any of the nanowiresdisclosed herein. In another embodiment the disclosure provides a methodof preparing low density polyethylene, high density polyethylene,ethylene dichloride, ethylene oxide, ethylbenzene, ethanol or vinylacetate from ethylene, wherein the ethylene has been prepared asdescribed above.

In another embodiment, the disclosure provides a method of preparing aproduct comprising low density polyethylene, high density polyethylene,ethylene dichloride, ethylene oxide, ethylbenzene, ethanol or vinylacetate, alkenes, alkanes, aromatics, alcohols, or mixtures thereof. Themethod comprises converting ethylene into low density polyethylene, highdensity polyethylene, ethylene dichloride, ethylene oxide, ethylbenzene,ethanol or vinyl acetate, wherein the ethylene has been prepared via acatalytic reaction employing a nanowires, for example any of theexemplary nanowires disclosed herein.

In more specific embodiments of any of the above methods, the ethyleneis produced via an OCM or ODH reaction.

In one particular embodiment, the disclosure provides a method ofpreparing a downstream product of ethylene and/or ethane, wherein thedownstream product is a hydrocarbon fuel. For example, the downstreamproduct of ethylene may be a C₄-C₁₄ hydrocarbon, including alkanes,alkenes and aromatics. Some specific examples include 1-butene,1-hexene, 1-octene, xylenes and the like. The method comprisesconverting methane into ethylene, ethane or combinations thereof by useof a catalytic nanowire, for example any of the catalytic nanowiresdisclosed herein, and further oligomerizing the ethylene and/or ethaneto prepare a downstream product of ethylene and/or ethane. For example,the methane may be converted to ethylene, ethane or combinations thereofvia the OCM reaction as discussed above. The catalytic nanowire may beany nanowire and is not limited with respect to morphology orcomposition. The catalytic nanowire may be an inorganic catalyticpolycrystalline nanowire, the nanowire having a ratio of effectivelength to actual length of less than one and an aspect ratio of greaterthan ten as measured by TEM in bright field mode at 5 keV, wherein thenanowire comprises one or more elements from any of Groups 1 through 7,lanthanides, actinides or combinations thereof. Alternatively, thecatalytic nanowire may be an inorganic nanowire comprising one or moremetal elements from any of Groups 1 through 7, lanthanides, actinides orcombinations thereof and a dopant comprising a metal element, asemi-metal element, a non-metal element or combinations thereof. Thenanowires may additionally comprise any number of doping elements asdiscussed above.

As depicted in FIG. 21, the method begins with charging methane (e.g.,as a component in natural gas) into an OCM reactor. The OCM reaction maythen be performed utilizing a nanowire under any variety of conditions.Water and CO₂ are optionally removed from the effluent and unreactedmethane is recirculated to the OCM reactor.

Ethylene is recovered and charged to an oligomerization reactor.Optionally the ethylene stream may contain CO₂, H₂O, N₂, ethane, C3'sand/or higher hydrocarbons. Oligomerization to higher hydrocarbons(e.g., C₄-C₁₄) then proceeds under any number of conditions known tothose of skill in the art. For example oligomerization may be effectedby use of any number of catalysts known to those skilled in the art.Examples of such catalysts include catalytic zeolites, crystallineborosilicate molecular sieves, homogeneous metal halide catalysts, Crcatalysts with pyrrole ligands or other catalysts. Exemplary methods forthe conversion of ethylene into higher hydrocarbon products aredisclosed in the following references: Catalysis Science & Technology(2011), 1(1), 69-75; Coordination Chemistry Reviews (2011), 255(7-8),861-880; Eur. Pat. Appl. (2011), EP 2287142 A1 20110223; Organometallics(2011), 30(5), 935-941; Designed Monomers and Polymers (2011), 14(1),1-23; Journal of Organometallic Chemistry 689 (2004) 3641-3668;Chemistry—A European Journal (2010), 16(26), 7670-7676; Acc. Chem. Res.2005, 38, 784-793; Journal of Organometallic Chemistry, 695 (10-11):1541-1549 May 15, 2010; Catalysis Today Volume 6, Issue 3, January 1990,Pages 329-349; U.S. Pat. No. 5,968,866; U.S. Pat. No. 6,800,702; U.S.Pat. No. 6,521,806; U.S. Pat. No. 7,829,749; U.S. Pat. No. 7,867,938;U.S. Pat. No. 7,910,670; U.S. Pat. No. 7,414,006 and Chem. Commun.,2002, 858-859, each of which are hereby incorporated in their entiretyby reference.

In certain embodiments, the exemplary OCM and oligomerization modulesdepicted in FIG. 21 may be adapted to be at the site of natural gasproduction, for example a natural gas field. Thus the natural gas can beefficiently converted to more valuable and readily transportablehydrocarbon commodities without the need for transport of the naturalgas to a processing facility.

Referring to FIG. 21, “natural gasoline” refers to a mixture ofoligomerized ethylene products. The mixture may comprise 1-hexene,1-octene, linear, branched or cyclic alkanes of 6 or more hydrocarbons,linear, branched, or cyclic alkenes of 6 or more hydrocarbons,aromatics, such as benzene, toluene, dimethyl benzene, xylenes,napthalene, or other oligomerized ethylene products and combinationsthereof. This mixture finds particular utility in any number ofindustrial applications, for example natural gasoline is used asfeedstock in oil refineries, as fuel blend stock by operators of fuelterminals, as diluents for heavy oils in oil pipelines and otherapplications. Other uses for natural gasoline are well-known to those ofskill in the art.

EXAMPLES Example 1 Genetic Engineering/Preparation of Phage

Phage were amplified in DH5 derivative E. coli (New England Biolabs,NEB5-alpha F′ lq; genotype: F′ proA+B+laclq Δ(lacZ)M15 zzf::Tn10(TetR)/fhuA2Δ(argF-lacZ)U169 phoA glnV44 φ80Δ(lacZ)M15 gyrA96 recA1endA1 thi-1 hsdR17) and purified using standard polyethylene glycol andsodium chloride precipitation protocols as described in the followingreferences: Kay, B. K.; Winter, J.; McCafferty, J. Phage Display ofPeptides and Proteins: A Laboratory Manual; Academic Press: San Diego(1996); C. F. Barbas, et al., ed., Phage Display: A Laboratory Manual;Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., USA(2001); and Joseph Sambrook and David W. Russell, Molecular Cloning, 3rdedition, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.,USA, 2001.

Example 2 Preparation of Phage Solutions

The phage solutions were additionally purified by centrifuging at anacceleration of 10000 g at least once (until no precipitated materialwas observed), decanting the supernatant and splitting it in 50 mlcontainers, which were then stored frozen at −20° C. The frozen phagesolutions were thawed only shortly before being used.

The concentration of the phage solutions was measured using a UV-VISspectrometer. The concentration of each of the frozen phage aliquots wasmeasured prior to use. This spectroscopic method relies on theabsorption of the nucleotides in the DNA of the phage and is describedin more detail in “Phage Display: A Laboratory Manual” by Barbas,Burton, Scott and Silverman (Cold Spring Harbor Laboratory Press, 2001).The concentration of phage solutions is expressed in pfu/ml (plagueforming units per milliliter).

Example 3 Preparation Mg(OH)₂ Nanowires

FIG. 12 shows a generic reaction scheme for preparing MgO nanowires(with dopant). First, the phage solution is thawed and its concentrationdetermined according to the method described above. The phage solutionis diluted with water to adjust its concentration in the reactionmixture (i.e. with all the ingredients added) to the desired value,typically 5e12 pfu/ml or higher. The reaction container can be anythingfrom a small vial (for milliliter scale reactions) up to large bottles(for liter reaction scale reactions).

A magnesium solution and a base solution are added to the phage solutionin order to precipitate Mg(OH)₂. The magnesium solution can be of anysoluble magnesium salt, e.g. MgX2.6H2O (X═Cl, Br, I), Mg(NO₃)₂, MgSO₄,magnesium acetate, etc. The range of the magnesium concentration in thereaction mixture is quite narrow, typically at 0.01M. The combination ofthe phage concentration and the magnesium concentration (i.e. the ratiobetween the pVIII proteins and magnesium ions) is very important indetermining both the nanowires formation process window and theirmorphology.

The base can be any alkali metal hydroxide (e.g. LiOH, NaOH, KOH),soluble alkaline earth metal hydroxide (e.g. Sr(OH)₂, Ba(OH)₂) or anyammonium hydroxide (e.g., NR₄OH, R═H, CH₃, C₂H₅, etc.). Certainselection criteria for the base include: adequate solubility (at leastseveral orders of magnitude higher than Mg(OH)₂ for Mg(OH)₂ nanowires),high enough strength (pH of the reaction mixture should be at least 11)and an inability to coordinate magnesium (for Mg(OH)₂ nanowires) to formsoluble products. LiOH is a preferred choice for Mg(OH)₂ nanowiresformation because lithium may additionally be incorporated in theMg(OH)₂ as a dopant, providing a Li/MgO doped catalyst for OCM.

Another factor concerning the base is the amount of base used or theconcentration ratio of OH⁻/Mg²⁺, i.e. the ratio between the number of OHequivalents added and the number of moles of Mg added. In order to fullyconvert the Mg ions in solution to Mg(OH)₂, the OH/Mg ratio needed is 2.The OH⁻/Mg²⁺ used in the formation of Mg(OH)₂ nanowires ranges from 0.5to 2 and, depending on this ratio, the morphology of the reactionproduct changes from thin nanowires to agglomerations of nanoparticles.The OH⁻/Mg²⁺ ratio is determined by the pH of the reaction mixture,which needs to be at least 11. If the pH is below 11, no precipitationis observed, i.e. no Mg(OH)₂ is formed. If the pH is above 12, themorphology of the nanowires begins to change and more nanoparticles areobtained, i.e. non-selective precipitation.

Considering the narrow window of magnesium concentration in which

Mg(OH)₂ nanowires can be obtained, the other key synthetic parametersthat determine the nanowires formation and morphology include but arenot limited to: phage sequence and concentration thereof, theconcentration ratio of Mg²⁺/pVIII protein, the concentration ratio ofOH⁻/Mg²⁺, the incubation time of phage and Mg²⁺; incubation time ofphage and the OH⁻; the sequence of adding anion and metal ions; pH; thesolution temperature in the incubation step and/or growth step; thetypes of metal precursor salt (e.g., MgCl₂ or Mg(NO₃)₂); the types ofanion precursor (e.g., NaOH or LiOH); the number of additions; the timethat lapses between the additions of the metal salt and anion precursor,including, e.g., simultaneous (zero lapse) or sequential additions.

The Mg salt solution and the base were added sequentially, separated byan incubation time (i.e., the first incubation time). The sequence ofaddition has an effect on the morphology of the nanowires. The firstincubation time can be at least 1 h and it should be longer in the casethe magnesium salt solution is added first. The Mg salt solution and thebase can be added in a single “shot” or in a continuous slow flow usinga syringe pump or in multiple small shots using a liquid dispenserrobot. The reaction is then carried either unstirred or with only mildto moderate stirring for a specific time (i.e., the second incubationtime). The second incubation time is not as strong a factor in thesynthesis of Mg(OH)₂ nanowires, but it should be long enough for thenanowires to precipitate out of the reaction solution (e.g., severalminutes). For practical reasons, the second incubation time can be aslong as several hours. The reaction temperature can be anything fromjust above freezing temperature (e.g., 4° C.) up to 80° C. Thetemperature affects the nanowires morphology.

The precipitated Mg(OH)₂ nanowires are isolated by centrifuging thereaction mixture and decanting the supernatant. The precipitatedmaterial is then washed at least once with a water solution with pH>10to avoid redissolution of the Mg(OH)₂ nanowires. Typically, the washingsolution used can be ammonium hydroxide water solution or an alkalimetal hydroxide solution (e.g., LiOH, NaOH, KOH). This mixture iscentrifuged and the supernatant decanted. Finally, the product can beeither dried (see, Example 5) or resuspended in ethanol for TEManalysis.

The decanted supernatant of the reaction mixture can be analyzed byUV-VIS to determine the phage concentration (see, Example 2) and thusgive an estimate of the amount of phage incorporated in the precipitatedMg(OH)₂, i.e. the amount of “mineralized” phage.

FIG. 12 depicts one embodiment for preparing Mg(OH)₂ nanowires. In adifferent embodiment, the order of addition may be reversed, for examplein an exemplary 4 ml scale synthesis of Mg(OH)₂ nanowires, 3.94 ml ofconcentrated solution of phages (e.g., SEQ ID NO: 3 at a concentrationof ˜5E12 pfu/ml) were mixed in a 8 ml vial with 0.02 ml of 1 M LiOHaqueous solution and left incubating overnight (˜15 h). 0.04 ml of 1 MMgCl₂ aqueous solution were then added using a pipette and the mixturewas mixed by gentle shaking. The reaction mixture was left incubatingunstirred for 24 h. After the incubation time, the mixture wascentrifuged, and the supernatant was decanted and saved for phageconcentration measurement by UV-VIS. The precipitated material wasresuspended in 2 ml of 0.001 M LiOH aqueous solution (pH=11), themixture was centrifuged and the supernatant decanted. The obtainedMg(OH)₂ nanowires were characterized by TEM as described in Example 4.

Example 4 Characterization of Mg(OH)₂ Nanowires

Mg(OH)₂ nanowires prepared according to Example 3 were characterized byTEM in order to determine their morphology. First, a few microliters(˜500) of ethanol was used to suspend the isolated Mg(OH)₂. Thenanowires were then deposited on a TEM grid (copper grid with a verythin carbon layer) placed on filter paper to help wick out any extraliquid. After allowing the ethanol to dry, the TEM grid was loaded in aTEM and characterized. TEM was carried out at 5 KeV in bright field modein a DeLong LVEM5.

The nanowires were additionally characterized by XRD (for phaseidentification) and TGA (for calcination optimization).

Example 5 Calcination of Mg(OH)₂ Nanowires

The isolated nanowires as prepared in Example 3 were dried in an oven atrelatively low temperature (60-120° C.) prior to calcination.

The dried material was placed in a ceramic boat and calcined in air at450° C. in order to convert the Mg(OH)₂ nanowires into MgO nanowires.The calcination recipe can be varied considerably. For example, thecalcination can be done relatively quickly like in these two examples:

-   -   load in a muffle oven preheated at 450° C., calcination time=120        min    -   load in a muffle oven (or tube furnace) at room temperature and        ramp to 450° C. with 5° C./min rate, calcination time=60 min

Alternatively, the calcination can be done in steps that are chosenaccording to the TGA signals like in the following example:

-   -   load in a muffle oven (or tube furnace) at room temperature,        ramp to 100° C. with 2° C./min rate, dwell for 60 min, ramp to        280° C. with 2° C./min rate, dwell for 60 min, ramp to 350° C.        with 2° C./min rate, dwell for 60 min and finally ramp to        450° C. with 2° C./min rate, dwell for 60 min.

Generally, a step recipe is preferable since it should allow for abetter, smoother and more complete conversion of Mg(OH)₂ into MgO.Optionally, the calcined product is ground into a fine powder.

FIG. 13 shows the X-ray diffraction patterns of the Mg(OH₂) nanowiresand the MgO nanowires following calcinations. Crystalline structures ofboth types of nanowires were confirmed.

Example 6 Preparation of Li Doped MgO Nanowires

Doping of nanowires is achieved by using the incipient wetnessimpregnation method. Before impregnating the MgO nanowires with thedoping solution, the maximum wettability (i.e. the ability of thenanowires to absorb the doping solution before becoming a suspension orbefore “free” liquid is observed) of the nanowires was determined. Thisis a very important step for an accurate absorption of the doping metalon the MgO surface. If too much dopant solution is added and asuspension is formed, a significant amount of dopant will crystallizeunabsorbed upon drying and if not enough dopant solution is added,significant portions of the MgO surface will not be doped.

In order to determine the maximum wettability of the MgO nanowires,small portions of water were dropped on the calcined MgO powder until asuspension was formed, i.e. until “free” liquid is observed. The maximumwettability was determined to be the total amount of water added beforethe suspension formed. The concentration of the doping solution was thencalculated so that the desired amount of dopant was contained in thevolume of doping solution corresponding to the maximum wettability ofthe MgO nanowires. In another way to describe the incipient wetnessimpregnation method, the volume of the doping solution is set to beequal to the pore volume of the nanowires, which can be determined byBET (Brunauer, Emmett, Teller) measurements. The doping solution is thendrawn into the pores by capillary action.

In one embodiment, the doping metal for MgO based catalysts for OCM islithium (see, also, FIG. 12). Thus, in one embodiment the dopant sourcecan be any soluble lithium salt as long as it does not introduceundesired contaminants. Typically, the lithium salts used were LiNO₃,LiOH or Li₂CO₃. LiNO₃ and LiOH are preferred because of their highersolubility. In one embodiment, the lithium content in MgO catalysts forOCM ranges from 0 to 10 wt % (i.e. about 0 to 56 at %).

The calculated amount of dopant solution of the desired concentrationwas dropped onto the calcined MgO nanowires. The obtained wet powder wasdried in an oven at relatively low temperature (60-120° C.) and calcinedusing one of the recipes described above. It is noted that, during thisstep, no phase transition occurs (MgO has already been formed in theprevious calcination step) and thus a step recipe (see previousparagraph) may not be necessary.

The dopant impregnation step can also be done prior to the calcination,after drying the Mg(OH)₂ nanowires isolated from the reaction mixture.In this case, the catalyst can be calcined immediately after the dopantimpregnation, i.e. no drying and second calcination steps would berequired since its goals are accomplished during the calcination step.

Three identical synthesis were made in parallel. In each synthesis, 80ml of concentrated solution of phages (SEQ ID NO: 3 at a concentrationof 5E¹² pfu/ml) were mixed in a 100 ml glass bottle with 0.4 ml of 1 MLiOH aqueous solution and left incubating for 1 h. 0.8 ml of 1 M MgCl₂aqueous solution were added using a pipette and the mixture was mixed bygently shaking it. The reaction mixture was left incubating unstirredfor 72 h at 60° C. in an oven. After the incubation time, the mixturewas centrifuged. The precipitated material was resuspended in 20 ml of0.06 M NH₄OH aqueous solution (pH=11), the mixture was centrifuged andthe supernatant decanted. The obtained Mg(OH)₂ nanowires wereresuspended in ethanol. The ethanol suspensions of the three identicalsyntheses were combined and a few microliters of the ethanol suspensionwere used for TEM analysis. The ethanol suspension was centrifuged andthe supernatant decanted. The gel-like product was transferred in aceramic boat and dried for 1 h at 120° C. in a vacuum oven.

The dried product was calcined in a tube furnace using a step recipe(load in the furnace at room temperature, ramp to 100° C. with 2° C./minrate, dwell for 60 min, ramp to 280° C. with 2° C./min rate, dwell for60 min, ramp to 350° C. with 2° C./min rate, dwell for 60 min, ramp to450° C. with 2° C./min rate, dwell for 60 min and finally cool to roomtemperature). The yield was 24 mg. The calcined product was ground to afine powder.

10 mg of the calcined product were impregnated with a LiOH aqueoussolution. First, the maximum wettability was determined by adding waterto the calcined product in a ceramic boat until the powder was saturatedbut no “free” liquid was observed. The maximum wettability was 12 μl.Since the target doping level was 1 wt % lithium, the necessaryconcentration of the LiOH aqueous solution was calculated to be 1.2 M.The calcined product was dried again for 1 h at 120° C. to remove thewater used to determine the wettability of the powder. 12 μl of the 1.2M LiOH solution were dropped on the MgO nanowires powder. The wet powderwas dried for 1 h at 120° C. in a vacuum oven and finally calcined in amuffle oven (load at room temperature, ramp to 460° C. with 2° C./minramp, dwell for 120 min).

Example 7 Creating Diversity by Varying the Reaction Parameters

Certain synthetic parameters strongly influence the nanowire formationon phage, including selective binding of metal and/or anions, as well assurface morphologies. FIG. 14 shows a number of MgO nanowiressynthesized in the presence of different phage sequence (e.g., differentpVIII) while keeping the other reaction conditions constant. Phages ofSEQ ID NOs. 1, 7, 10, 11, 13 and 14 were the respective phage of choicein six reactions carried out in otherwise identical conditions. Theconstant reaction conditions may include: concentration ratios of Mg²⁺and active functional groups on the phage; concentration ratios ofOH⁻/Mg²⁺; incubation time of phage and Mg²⁺; incubation time of phageand OH⁻; concentration of phage; sequence of adding anion and metalions; solution temperature in the incubation step and/or growth step;etc. As shown, the morphologies of MgO nanowires are significantlyinfluenced by the phage sequences.

Thus, varying these and other reaction conditions may produce a diverseclass of nanowire catalysts. In addition, certain correlation betweenthe reaction conditions and the surface morphologies of the nanowirescan be empirically established, thus enabling rational designs ofcatalytic nanowires.

Example 8 Preparation of Sr-Doped La₂O₃ Nanowires

23 ml of 2.5 e12 pfu solution of phages (SEQ ID NO: 3) was mixed in a 40ml glass bottle with 0.046 ml of 0.1 M LaCl₃ aqueous solution and leftincubating for 16 h. After this incubation period, a slow multistepaddition is conducted with 1.15 ml of 0.05 M LaCl₃ solution and 1.84 mlof 0.3 M NH₄OH. This addition is conducted in six hours and twentysteps. The reaction mixture was left stirred another 2 h at roomtemperature. After that time the suspension was centrifuged in order toseparate the solid phase from the liquid phase. The precipitatedmaterial was then resuspended in 5 ml of water and centrifuged in orderto further remove un-reacted species. A final wash was conducted with 2ml ethanol. The gel-like product remaining is then dried for 30 minutesat 110° C. in a vacuum oven.

The dried product was then calcined in a muffle furnace using a steprecipe (load in the furnace at room temperature, ramp to 200° C. with 3°C./min rate, dwell for 120 min, ramp to 400° C. with 3° C./min rate,dwell for 120 min, cool to room temperature). The calcined product wasthen ground to a fine powder.

5 mg of the calcined product were impregnated with 0.015 ml Sr(NO₃)₂0.1M aqueous solution. Powder and solution is mixed on hot plate at 90 Cuntil forming a paste. The paste was then dried for 1 h at 120° C. in avacuum oven and finally calcined in a muffle oven in air. (load in thefurnace at room temperature, ramp to 200° C. with 3° C./min rate, dwellfor 120 min, ramp to 400° C. with 3° C./min rate, dwell for 120 min,ramp to 500° C. with 3° C./min rate, dwell for 120 min, cool to roomtemperature).

Example 9 Preparation of ZrO₂/La₂O₃ Core/Shell Nanowires

As an example, FIG. 15 shows schematically an integrated process 800 forgrowing a core/shell structure of ZrO₂/La₂O₃ nanowire. A phase solutionis prepared, to which a zirconium salt precursor (e.g., ZrCl₂) is addedto allow for the nucleation of ZrO²⁺ on the phage. Subsequently, ahydroxide precursor (e.g., LiOH) is added to cause the nucleation ofhydroxide ions on the phage. Nanowires 804 is thus formed in which thephage 810 is coated with a continuous and crystalline layer 820 ofZrO(OH)₂. To this reaction mixture, a lanthanum salt precursor (e.g.,LaCl₃) is added under a condition to cause the nucleation of La(OH)₃over the ZrO(OH)₂ nanowire 804. Following calcinations, nanowires of acore/shell structure of ZrO₂/La₂O₃ are formed. A further step ofimpregnation produces nanowires of ZrO₂/La₂O₃ doped with strontium ions(Sr²⁺) 840, in which the phage 810 is coated with a layer of ZrO₂ 830,which is in turn coated with a shell of La₂O₃ 850.

ZrO₂/La₂O₃ nanowires were thus prepared by mixing 20 ml of 2.5e12 pfu E³Phage solution to 0.1 ml of 0.5M ZrO(NO₃)₂ aqueous solution. Thesolution was incubated under stirring for 16 hours. Any solids formedfollowing incubation were removed by centrifugation at 4000 rpm for 5minutes and redispersed in 0.5 ml ethanol. A small aliquot was retrievedfor TEM characterization.

Thereafter, the ethanol solution was mixed with 10 ml water and 2 ml of0.05M ZrO(NO₃)₂ with 2 ml of 0.1 M NH₄OH were added during a period of200 minutes using syringe pumps. Wash solids with water and resuspend inethanol for TEM observation.

To about 18 mg of ZrO(OH)₂ nanowires in suspension, 10 ml of water wasadded, followed by the addition of 0.5 ml of LaCl₃ 0.083 M with 0.5 mlof NH₄OH 0.3 M solution during a period of 50 minutes using syringepumps. The solids thus formed were separated by centrifugation to obtaina powder, which was dried in a vacuum oven at 110° C. for one hour. Asmall aliquot of the dried powder is then suspended in ethanol for TEMobservation.

Example 10 Preparation of La(OH)₃/ZrO₂ Core/Shell Nanowires

Similar to Example 9, La(OH)₃ nanowires were coated with ZrO₂ shellaccording to the following process. To 6.8 mg of La(OH)₃ nanowires(prepared by LaCl₃ and NH₄OH in a process similar to that of Example 9),which had been dried at 110° C., was added 4 ml of water to suspend thesolids. 0.5 ml of 0.05M ZrO(NO₃)₂ and 0.5 ml of 0.1 M NH₄OH were slowlyadded in 50 minutes. The solids were retrieved by centrifugation andcalcined at 500° C. for one hour. TEM observation showed nanowires asthe major morphology.

Example 11 Preparation of Hollow-Cored ZrO₂ Nanowires

To the La(OH)₃/ZrO₂ core/shell nanowires prepared Example 10, additionalprocessing can be used to create hollow ZrO₂ shell nanowires. TheLa(OH)₃ core can be etched using 1M citric acid solution. Controlledexperiments on calcined and un-calcined La(OH)₃ nanowires shows that theentire nanowires are fully etched in about one hour at room temperature.Etching of La(OH)₃/ZrO₂ core/shell nanowires was conducted overnight(about 16 hours).

The remaining solid was then separated by centrifugation and TEMobservation is conducted on the washed solids (water wash). Low contrastzirconia nanowires were observed after etching, which indicates thathollow zirconia “straws” can be formed using La(OH)₃ nanowire astemplate.

Example 12 OCM Catalyzed by La₂O₃ Nanowires

A 20 mg sample of a phage-based Sr (5%) doped La₂O₃ catalyst was dilutedwith 80 mg of quartz sand and placed into a reactor (run WPS21). The gasflows were held constant at 9 sccm methane, 3 sccm oxygen and 6 sccm ofargon. The upstream temperature (just above the bed) was varied from500° C. to 800° C. in 100° C. increments and then decreased back down to600° C. in 50° C. increments. The vent gas analysis was gathered at eachtemperature level.

As a point of comparison, 20 mg of bulk 5% Sr on La₂O₃ catalyst wasdiluted in the same manner and run through the exact flow andtemperature protocol.

FIG. 16 shows the formation of OCM products at 700° C., including C2(ethane and ethylene) as well as further coupling products (propane andpropylene).

FIGS. 17A, 17B and 17C show the comparative results in catalyticperformance parameters for a nanowire catalyst (Sr²⁺/La₂O₃) vs. itscorresponding bulk material (Sr²⁺/La₂O₃ bulk). Methane conversion rates,C2 selectivities and C2 yields are among the important parameters bywhich the catalytic properties were measured. More specifically, FIG.17A shows the methane conversion rates are higher for the nanowirecatalyst compared to the bulk material across a wide temperature range(e.g., 550 to 650° C.). Likewise, FIG. 17B and FIG. 17C show that the C2selectivities and C2 yields are also higher for the nanowire catalyst ascompared to the bulk catalyst across a wide temperature range (e.g., 550to 650° C.). Thus, it is demonstrated that by improving both conversionand selectivity simultaneously that the C2 yield can be improved overtraditional bulk catalysts.

FIGS. 18A-18B demonstrate that nanowires prepared under differentsynthetic conditions afforded different catalytic performances,suggesting that the various synthetic parameters resulted in divergentnanowire morphologies. FIG. 18A shows that nanowires prepared usingdifferent phage templates (SEQ ID NO: 9 and SEQ ID NO:3) in otherwiseidentical synthetic conditions created nanowire catalysts that performdifferently in terms of the C2 selectivity in an OCM reaction. FIG. 18Bshows the comparative C2 selectivities of nanowires prepared by analternative adjustment of the synthetic parameters. In this case, thephage template was the same for both nanowires (SEQ ID NO:3), but thesynthetic conditions were different. Specifically, the nanowires of FIG.18A were prepared with shorter incubation and growth times than thenanowires of FIG. 18B. Additionally, the nanowires of FIG. 18A werecalcined in a single step at 400° C. instead of the ramped temperaturecalcinations performed on the nanowires of FIG. 18B.

These results confirm that the nanowire catalysts behave differentlyfrom their bulk material counterparts. In particular, the nanowirecatalysts allow for adjustments of the surface morphologies throughsynthetic design and screening to ultimately produce high-performancecatalysts.

Example 13 Oxidative Dehydrogenation Catalyzed by MgO Nanowires

A 10 mg sample of phage-based Li doped MgO catalyst was diluted with 90mg of quartz sand and placed in a reactor. The gas flows were heldconstant at 8 sccm alkane mix, 2 sccm oxygen and 10 sccm of argon. Theupstream temperature (just above the bed) was varied from 500° C. to750° C. in 50-100° C. increments. The vent gas analysis was gathered ateach temperature level.

As a point of comparison, 10 mg of bulk 1 wt % Li on MgO catalyst wasdiluted in the same manner and run through the exact flow andtemperature protocol. The results of this experiment are shown in FIG.19. As can be seen in FIG. 19, phage-based nanowires according to thepresent disclosure comprise better conversion of ethane and propanecompared to a corresponding bulk catalyst.

Example 14 Synthesis of Sr Doped La₂O₃ Nanowires

Sr doped La₂O₃ nanowires were prepared according to the followingnon-template directed method.

A La(OH)₃ gel was prepared by adding 0.395 g of NH₄OH (25%) to 19.2 mlof water followed by addition of 2 ml of a 1 M solution of La(NO₃)₃. Thesolution was then mixed vigorously. The solution first gelled but theviscosity dropped with continuous agitation. The solution was thenallowed to stand for a period of between 5 and 10 minutes. The solutionwas then centrifuged at 10,000 g for 5 minutes. The centrifuged gel wasretrieved and washed with 30 ml of water and the centrifugation washingprocedure was repeated.

To the washed gel was added 10.8 ml of water to suspend the solid. Thesuspension was then transferred to a hydrothermal bomb (20 ml volume,not stirred). The hydrothermal bomb was then loaded in a muffle furnaceat 160° C. and the solution was allowed to stand under autogenouspressure at 160° C. for 16 hours.

The solids were then isolated by centrifugation at 10,000 g for 5minutes, and wash with 10 ml of water to yield about 260 mg of solid(after drying). The obtained solids were calcined in a muffle ovenaccording to the following procedure: (1) load in the furnace at roomtemperature; (2) ramp to 200° C. with 3° C./min rate; (3) dwell for 120min; (4) ramp to 400° C. with 3° C./min rate; and (5) dwell for 120 min.About 220 mg of nanowires were retrieved after calcination.

A 57 mg aliquot of nanowires was then mixed with 0.174 ml of a 0.1 Msolution of Sr(NO₃)₂. This mixture was then stirred on a hot plate at90° C. until a paste was formed.

The paste was then dried for 1 h at 120° C. in a vacuum oven and finallycalcined in a muffle oven in air according to the following procedure:(1) load in the furnace at room temperature; (2) ramp to 200° C. with 3°C./min rate; (3) dwell for 120 min; (3) ramp to 400° C. with 3° C./minrate; (4) dwell for 120 min; (5) ramp to 500° C. with 3° C./min rate;and (6) dwell for 120 min. The calcined product was then ground to afine powder.

5 mg of the calcined product were impregnated with 0.015 ml Sr(NO₃)₂0.1M aqueous solution. Powder and solution is mixed on hot plate at 90 Cuntil forming a paste. The paste was then dried for 1 h at 120° C. in avacuum oven and finally calcined in a muffle oven in air. (load in thefurnace at room temperature, ramp to 200° C. with 3° C./min rate, dwellfor 120 min, ramp to 400° C. with 3° C./min rate, dwell for 120 min,ramp to 500° C. with 3° C./min rate, dwell for 120 min).

FIG. 20 shows a TEM image of the nanowires obtained from thisnon-template directed method. As shown in FIG. 20, the nanowirescomprise a ratio of effective length to actual length of about 1 (i.e.,the nanowires comprise a “straight” morphology).

Example 15 Synthesis of La₂O₃ Nanowires

La(NO₃)₃.6H₂O (10.825 g) is added to 250 mL distilled water and stirreduntil all solids are dissolved. Concentrated ammonium hydroxide (4.885mL) is added to this mixture and stirred for at least one hour resultingin a white gel. This mixture is transferred equally to 5 centrifugetubes and centrifuged for at least 15 minutes. The supernatant isdiscarded and each pellet is rinsed with water, centrifuged for at least15 minutes and the supernatant is again discarded.

The resulting pellets are all combined, suspended in distilled water(125 mL) and heated at 105° C. for 24 hours. The lanthanum hydroxide isisolated by centrifugation and suspended in ethanol (20 mL). The ethanolsupernatant is concentrated and the product is dried at 65° C. until allethanol is removed.

The lanthanum hydroxide nanowires prepared above are calcined by heatingat 100° C. for 30 min., 400° C. for 4 hours and then 550° C. for 4 hoursto obtain the La₂O₃ nanowires.

Example 16 Preparation of Na₁₀MnW₅O₁₇ Nanowires

25 ml of concentrated reagent grade NH₄OH are dissolved in 25 ml ofdistilled water, and 1 ml of 0.001M aqueous solution of M13bacteriophage is then added. 0.62 g of Mn(NO₃)₂, 1.01 g of NaCl and 2.00g of WO₃ are then added to the mixture with stirring. The mixture isheated at a temperature of about 95° C. for 15 minutes. The mixture isthen dried overnight at about 110° C. and calcined at about 400° C. for3 hours.

Example 17 Preparation of Na₁₀MnW₅O₁₇ Nanowires

25 ml of concentrated reagent grade NH₄OH are dissolved in 25 ml ofdistilled water, and 1 ml of 0.001 M aqueous solution of M13bacteriophage is then added. 1.01 g of NaCl and 2.00 g of WO₃ are thenadded to the mixture with stirring. The mixture is heated at atemperature of about 95° C. for 15 minutes. The mixture is then driedovernight at about 110° C. and calcined at about 400° C. for 3 hours.The resulting material is then suspended in 10 ml of distilled water and0.62 g of Mn(NO₃)₂ is added to the mixture with stirring. The mixture isheated at a temperature of about 115° C. for 15 minutes. The mixture isthen dried overnight at about 110° C. and calcined at about 400° C. for3 hours.

Example 18 Preparation of Na₁₀MnW₅O₁₇/SiO₂ Nanowires

Nanowire material Na₁₀MnW₅O₁₇ (2.00 g), prepared as described in Example16 above, is suspended in water, and about 221.20 g of a 40% by weightcolloidal dispersion of SiO₂ (silica) is added while stirring. Themixture is heated at about 100° C. until near dryness. The mixture isthen dried overnight at about 110° C. and heated under a stream ofoxygen gas (i.e., calcined) at about 400° C. for 3 hours. The calcinedproduct is cooled to room temperature and then ground to a 10-30 meshsize.

Example 19 Preparation of La₂O₃ Nanowires

Two identical syntheses were made in parallel. In each synthesis, 360 mlof 4 e12 pfu/ml solution of phage (SEQ ID NO: 3) were mixed in a 500 mlplastic bottle with 1.6 ml of 0.1 M LaCl3 aqueous solution and leftincubating for at least 1 hour. After this incubation period, a slowmultistep addition was conducted with 20 ml of 0.1 M LaCl3 solution and40 ml of 0.3 M NH4OH. This addition was conducted in 24 hours and 100steps. The reaction mixture was left stirred for at least another hourat room temperature. After that time the suspension was centrifuged inorder to separate the solid phase from the liquid phase. Theprecipitated material was then re-suspended in 25 ml of ethanol. Theethanol suspensions from the two identical syntheses were combined andcentrifuged in order to remove un-reacted species. The gel-like productremaining was then dried for 15 hours at 65° C. in an oven and thencalcined in a muffle oven in air (load in the furnace at roomtemperature, ramp to 100° C. with 2° C./min rate, dwell for 30 min, rampto 400° C. with 2° C./min rate, dwell for 240 min, ramp to 550° C. with2° C./min rate, dwell for 240 min, cool to room temperature).

Example 20 Preparation of Mg/Na Doped La₂O₃ Nanowires

Two identical syntheses were made in parallel. In each synthesis, 360 mlof 4 e12 pfu solution of phage (SEQ ID NO: 3) were mixed in a 500 mlplastic bottle with 1.6 ml of 0.1 M LaCl₃ aqueous solution and leftincubating for at least 1 hour. After this incubation period, a slowmultistep addition was conducted with 20 ml of 0.1 M LaCl₃ solution and40 ml of 0.3 M NH₄OH. This addition was conducted in 24 hours and 100steps. The reaction mixture was left stirred for at least another hourat room temperature. After that time, the suspension was centrifuged inorder to separate the solid phase from the liquid phase. Theprecipitated material was then resuspended in 25 ml of ethanol. Theethanol suspensions from the two identical syntheses were combined andcentrifuged in order to remove un-reacted species. The gel-like productremaining was then dried for 15 hours at 65° C. in an oven.

The target doping level was 20 at % Mg and 5 at % Na at % refers toatomic percent). 182 mg of the dried product were suspended in 2.16 mldeionized water, 0.19 ml 1 M Mg(NO₃)₂ aqueous solution and 0.05 ml 1MNaNO₃ aqueous solution. The resulting slurry was stirred at roomtemperature for 1 hour, sonicated for 5 min, then dried at 120° C. inand oven until the powder was fully dried and finally calcined in amuffle oven in air (load in the furnace at room temperature, ramp to100° C. with 2° C./min rate, dwell for 30 min, ramp to 400° C. with 2°C./min rate, dwell for 60 min, ramp to 550° C. with 2° C./min rate,dwell for 60 min, ramp to 650° C. with 2° C./min rate, dwell for 60 min,ramp to 750° C. with 2° C./min rate, dwell for 240 min, cool to roomtemperature).

Example 21 Oxidative Coupling of Methane Catalyzed by Mg/Na Doped La₂O₃Nanowires

50 mg of Mg/Na-doped La₂O₃ nanowires catalyst from example 20 wereplaced into a reactor tube (4 mm ID diameter quartz tube with a 0.5 mmID capillary downstream), which was then tested in an Altamira Benchcat203. The gas flows were held constant at 46 sccm methane and 54 sccmair, which correspond to a CH₄/O₂ ratio of 4 and a feed gas-hour spacevelocity (GHSV) of about 130000 h-1. The reactor temperature was variedfrom 400° C. to 450° C. in a 50° C. increment, from 450° C. to 550° C.in 25° C. increments and from 550° C. to 750° C. in 50° C. increments.The vent gases were analyzed with gas chromatography (GC) at eachtemperature level.

FIG. 22 shows the onset of OCM between 550° C. and 600° C. The C2selectivity, methane conversion and C2 yield at 650° C. were 57%, 25%and 14%, respectively.

In another example, 50 mg of Mg/Na-doped La₂O₃ nanowires catalyst fromexample 20 were placed into a reactor tube (4 mm ID diameter quartz tubewith a 0.5 mm ID capillary downstream), which was then tested in anAltamira Benchcat 203. The gas flows were held constant at 46 sccmmethane and 54 sccm air, which correspond to a feed gas-hour spacevelocity (GHSV) of about 130000 h⁻¹. The CH4/O2 ratio was 5.5. Thereactor temperature was varied from 400° C. to 450° C. in a 50° C.increment, from 450° C. to 550° C. in a 25° C. increments and from 550°C. to 750° C. in 50° C. increments. The vent gases were analyzed withgas chromatography (GC) at each temperature level.

FIG. 23 shows the onset of OCM between 550° C. and 600° C. The C2selectivity, methane conversion and C2 yield at 650° C. were 62%, 20%and 12%, respectively.

Example 22 Nanowire Synthesis

Nanowires may be prepared by hydrothermal synthesis from metal hydroxidegels (made from metal salt+base). In some embodiments, this method isapplicable to lanthanides, for example La, Nd, Pr, Sm, Eu, andlanthanide containing mixed oxides.

Alternatively, nanowires can be prepared by synthesis from metalhydroxide gel (made from metal salt+base) under reflux conditions. Insome embodiments, this method is applicable to lanthanides, for exampleLa, Nd, Pr, Sm, Eu, and lanthanide containing mixed oxides.

Alternatively, the gel can be aged at room temperature. Certainembodiments of this method are applicable for making magnesiumhydroxychloride nanowires, which can be converted to magnesium hydroxidenanowires and eventually to MgO nanowires. In a related method,hydrothermal treatment of the gel instead of aging, is used.

Nanowires may also be prepared by polyethyleneglycol assistedhydrothermal synthesis. For example, Mn containing nanowires may beprepared according to this method using methods known to those skilledin the art. Alternatively, hydrothermal synthesis directly from theoxide can be used.

Example 23 Preparation of Nanowires

Nanostructured catalyst materials can be prepared by a variety ofstarting materials. In certain embodiments, the rare earth oxides areattractive starting materials since they can be obtained at high purityand are less expensive than the rare earth salt precursors that aretypically used in preparative synthesis work. Methods for making rareearth oxide needles/nanowires and derivatives thereof are describedbelow.

Method A: Lanthanide oxide starting material can be hydrothermallytreated in the presence of ammonium halide to prepare rare earth oxidenanowires/needles. The preparation is a simple one-pot procedure withhigh yield. For example, one gram of lanthanum oxide was placed in 10 mLof distilled water. Ammonium chloride (0.98 g) was added to the water,the mixture was placed in an autoclave, and the autoclave was placed ina 160 C oven for 18 h. The autoclave was taken out of the oven, cooled,and the product was isolated by filtration. Micron and submicron needleswere observed in the TEM images of the product. This method could alsobe used to prepare mixed metal oxides, metal oxyhalides, metaloxynitrates, and metal sulfates.

Method B: Mixed metal oxide materials can be prepared using asolid-state reaction of rare earth oxide or bismuth oxide in thepresence of ammonium halide. The solid-state reaction is used to preparethe rare earth or bismuth oxyhalide. The metal oxyhalide is then placedin water at room temperature and the oxyhalide is slowly converted tometal oxide with nanowire/needle morphology. For example: lanthanumoxide, bismuth oxide, and ammonium chloride were ground and fired in aceramic dish to make the mixed metal oxychloride. The metal oxychlorideis then placed in water to form the mixed metal oxide needles.

Example 24 Preparation of MgO/Mn₂O₃ Core/Shell Nanowires

19.7 ml of concentrated solution of phages (e.g., SEQ ID NO: 3 at aconcentration of ˜5E12 pfu/ml) were mixed in a 20 ml vial with 0.1 ml of1 M LiOH aqueous solution and left incubating overnight (˜15 h). 0.2 mlof 1 M MgCl₂ aqueous solution were then added using a pipette, and themixture was mixed by gentle shaking. The reaction mixture was leftincubating unstirred for 72 h. After the incubation time, the mixturewas centrifuged and the supernatant decanted. The precipitated materialwas re-suspended in 5 ml of 0.001 M LiOH aqueous solution (pH=11), themixture was centrifuged and the supernatant decanted.

19.8 ml of deionized water were added to the obtained Mg(OH)₂ nanowires.The mixture was left incubating for 1 h. After the incubation time, 0.2ml of 1 M MnCl₂ aqueous solution were then added using a pipette and themixture was mixed by gentle shaking. The reaction mixture was leftincubating unstirred for 24 h. After the incubation time, the mixturewas centrifuged and the supernatant decanted. The precipitated materialwas re-suspended in 3 ml of 0.001 M LiOH aqueous solution (pH=11), themixture was centrifuged and the supernatant decanted. The precipitatedmaterial was finally re-suspended in 7 ml ethanol, the mixture wascentrifuged and the supernatant decanted.

The obtained MnO(OH) coated Mg(OH)₂ nanowires were dried at 65° C. for15 h in an oven. Finally, the dried product was calcined in a mufflefurnace using a step recipe (load in the furnace at room temperature,ramp to 100° C. with 2° C./min rate, dwell for 60 min, ramp to 280° C.with 2° C./min rate, dwell for 60 min, ramp to 350° C. with 2° C./minrate, dwell for 60 min, ramp to 450° C. with 2° C./min rate, dwell for60 min, ramp to 550° C. with 2° C./min rate, dwell for 60 min, cool toroom temperature) to convert it to MgO/Mn₂O₃ core-shell nanowires.

The surface area of the nanowires was determined by BET (Brunauer,Emmett, Teller) measurement at 111.5 m²/g.

Example 25 Preparation of Mn₂O₃ Nanowires

3.96 ml of concentrated solution of phages (e.g., SEQ ID NO: 3 at aconcentration of ˜5E12 pfu/ml) were mixed in a 8 ml vial with 0.04 ml of1 M MnCl₂ aqueous solution and left incubating for 20 h. 0.02 ml of 1 MLiOH aqueous solution were then added using a pipette and the mixturewas mixed by gentle shaking. The reaction mixture was left incubatingunstirred for 72 h. After the incubation time, the mixture wascentrifuged, and the supernatant was decanted. The precipitated materialwas re-suspended in 2 ml of 0.001 M LiOH aqueous solution (pH=11), themixture was centrifuged and the supernatant decanted. The precipitatedmaterial was re-suspended in 2 ml ethanol, the mixture was centrifugedand the supernatant decanted. The obtained MnO(OH) nanowires were driedat 65° C. for 15 h in an oven. Finally, the dried product was calcinedin a muffle furnace using a step recipe (load in the furnace at roomtemperature, ramp to 100° C. with 2° C./min rate, dwell for 60 min, rampto 280° C. with 2° C./min rate, dwell for 60 min, ramp to 350° C. with2° C./min rate, dwell for 60 min, ramp to 450° C. with 2° C./min rate,dwell for 60 min, ramp to 550° C. with 2° C./min rate, dwell for 60 min,cool to room temperature) to convert it to Mn₂O₃ nanowires.

Example 26 Preparation of V₂O₅ Nanowires

1.8 mg of V₂O₅ were dissolved in a 10 ml of a 2.5 wt % aqueous solutionof HF. 1 ml of the V₂O₅/HF solution was mixed with 1 ml of concentratedsolution of phages (e.g., SEQ ID NO: 3 at a concentration of ˜5E12pfu/ml) in a 15 ml plastic centrifugation tube and left incubating for 2h. 1 ml of a saturated solution of boric acid (supernatant of nominally1 M boric acid aqueous solution) were then added using a pipette and themixture was mixed by gentle shaking. The reaction mixture was leftincubating unstirred for 170 h. After the incubation time, the mixturewas centrifuged, and the supernatant was decanted. The precipitatedmaterial was suspended in 2 ml ethanol, the mixture was centrifuged andthe supernatant decanted. The obtained V₂O₅ nanowires were characterizedby TEM.

Example 27

Synthesis of MgO Nanowires

12.5 ml of a 4M MgCl₂ aqueous solution were heated to 70° C. on ahotplate. 0.1 g of MgO (from Aldrich) were then slowly added, over aspan of at least 5 minutes, to the solution while it was vigorouslystirred. The mixture was kept stirring at 70° C. for 3 h and then cooleddown overnight (˜15 h) without stirring.

The obtained gel was transferred in a 25 ml hydrothermal bomb (Parr BombNo. 4749). The hydrothermal bomb was then loaded in an oven at 120° C.and the solution was allowed to stand under autogenous pressure at 120°C. for 3 hours.

The product was centrifuged and the supernatant decanted. Theprecipitated product was suspended in about 50 ml ethanol and filteredover a 0.45 m polypropylene hydrophilic filter using a Büchner funnel.Additional 200 ml ethanol were used to wash the product.

The obtained magnesium hydroxide chloride hydrate nanowires weresuspended in 12 ml ethanol and 2.4 ml deionized water in a 20 ml vial.1.6 ml of 5M NaOH aqueous solution were added and the vial was sealedwith its cap. The mixture was then heated at 65° C. in an oven for 15 h.

The product was filtered over a 0.45 μm polypropylene hydrophilic filterusing a Büchner funnel. About 250 ml ethanol were used to wash theproduct. The obtained Mg(OH)₂ nanowires were dried at 65° C. for 15 h inan oven. Finally, the dried product was calcined in a muffle furnaceusing a step recipe (load in the furnace at room temperature, ramp to100° C. with 2° C./min rate, dwell for 60 min, ramp to 280° C. with 2°C./min rate, dwell for 60 min, ramp to 350° C. with 2° C./min rate,dwell for 60 min, ramp to 450° C. with 2° C./min rate, dwell for 60 min,cool to room temperature) to convert it to MgO nanowires.

Example 28 Synthesis of Mg(OH)₂ Nanowires

6.8 g of MgCl₂.6H₂O were dissolved in 5 ml deionized water in a 20 mlvial. 0.4 g of MgO (from Aldrich) were then slowly added to the solutionwhile it was vigorously stirred. The mixture was kept stirring at roomtemperature until it completely jellified (˜2 h) and then it was leftaging for 48 h without stirring.

The gel was transferred in a 50 ml centrifuge tube, which was thenfilled with deionized water and vigorously shaken until an homogenoussuspension was obtained. The suspension was centrifuged and thesupernatant decanted. The precipitated product was suspended in about 50ml ethanol and filtered over a 0.45 m polypropylene hydrophilic filterusing a Büchner funnel. Additional 350 ml ethanol were used to wash theproduct.

The obtained magnesium hydroxide chloride hydrate nanowires weresuspended in 24 ml ethanol in a 50 ml media bottle. The mixture wasstirred for a few minutes, then 4.8 ml deionized water and 3.2 ml of 5MNaOH aqueous solution were added. The media bottle was sealed with itscap and the mixture was stirred for few more minutes. The mixture wasthen heated at 65° C. in an oven for 15 h.

The product was filtered over a 0.45 μm polypropylene hydrophilic filterusing a Büchner funnel. About 400 ml ethanol were used to wash theproduct. The obtained Mg(OH)₂ nanowires were dried at 65° C. for 72 h inan oven and then additionally dried at 120° C. for 2 h in a vacuum oven.About 0.697 g of Mg(OH)₂ nanowires were obtained and the surface area ofthe nanowires was determined by BET (Brunauer, Emmett, Teller)measurement at 100.4 m²/g.

Example 29 Synthesis of MnO/Mn₂O₃ Core/Shell Nanowires

This example describes a method for coating the Mg(OH)₂ nanowires fromexample 28 with MnO(OH).

Three almost identical syntheses were conducted in parallel. In eachsynthesis, the Mg(OH)₂ nanowires, prepared using the method described inexample 28 but without the drying steps, were mixed with 250 mldeionized water in a 500 ml plastic bottle and stirred for 20 minutes.2.4 ml of a 1M MnCl₂ solution were added to the first synthesis, 6 ml ofa 1M MnCl₂ solution were added to the second synthesis and 9.6 ml of a1M MnCl₂ solution were added to the third synthesis. The mixtures werestirred for 2 hours at room temperature. After this incubation period, aslow multistep addition was conducted with 1.2 ml, 3 ml and 4.8 ml of0.1 M LiOH solution for the first, second and third synthesis,respectively. This addition was conducted in 2 hours and 20 steps. Thereaction mixture was left stirred overnight (˜15 h) at room temperature.After that time the suspensions were centrifuged in order to separatethe solid phase from the liquid phase. The precipitated materials werethen re-suspended in 50 ml of ethanol for each synthesis and filteredover a 0.45 μM polypropylene hydrophilic filter using a Büchner funnel.Additional 350 ml ethanol were used to wash each product of the threesynthesis.

The obtained Mg(OH)₂/MnO(OH) core/shell nanowires were characterized byTEM before being dried at 65° C. for 72 h in an oven and thenadditionally dried at 120° C. for 2 h in a vacuum oven. The yield forthe three syntheses was 0.675 g, 0.653 g and 0.688 g, respectively. Thesurface area of the nanowires was determined by BET (Brunauer, Emmett,Teller) measurement at 94.6 m²/g, 108.8 m²/g and 108.7 m²/g,respectively.

The Mg(OH)₂/MnO(OH) core/shell nanowires can be converted into MgO/Mn₂O₃nanowires by calcining them in a muffle furnace using a step recipe(load in the furnace at room temperature, ramp to 100° C. with 2° C./minrate, dwell for 60 min, ramp to 280° C. with 2° C./min rate, dwell for60 min, ramp to 350° C. with 2° C./min rate, dwell for 60 min, ramp to450° C. with 2° C./min rate, dwell for 60 min, ramp to 550° C. with 2°C./min rate, dwell for 60 min, cool to room temperature).

Example 30 Preparation of Nd₂O₃, Eu₂O₃ and Pr₂O₃ Nanowires

Three syntheses were made in parallel. In each synthesis, 10 ml of a 2.5e12 pfu/ml solution of phage (SEQ ID NO: 14) were mixed in a 60 ml glassvial with 25 μl of 0.08M NdCl₃, EuCl₃ or PrCl₃ aqueous solutions,respectively and left incubating for at least 1 hour. After thisincubation period, a slow multistep addition was conducted with 630 μlof 0.08M LaCl₃, EuCl₃ or PrCl₃ aqueous solutions, respectively and 500μl of 0.3M NH₄OH. This addition was conducted in 33 hours and 60 steps.The reaction mixtures were left stirred for at least another 10 hour atroom temperature. After that time the suspensions were centrifuged inorder to separate the solid phase from the liquid phase. Theprecipitated material was then re-suspended in 4 ml of ethanol. Theethanol suspensions were centrifuged in order to finish removingun-reacted species. The gel-like product remaining was then dried for 1hours at 65° C. in an oven and then calcined in a muffle oven in air(load in the furnace at room temperature, ramp to 100° C. with 2° C./minrate, dwell for 30 min, ramp to 500° C. with 2° C./min rate, dwell for240 min, cool to room temperature). The obtained Nd(OH)₃, Eu(OH)₃ andPr(OH)₃ nanowires were characterized by TEM before being dried.

Example 31 Preparation of Ce₂O₃/La₂O₃ Mixed Oxide Nanowires

In the synthesis, 15 ml of a 5 e12 pfu/ml solution of phage (SEQ ID NO:3) were mixed in a 60 ml glass vial with 15 μl of 0.1 M La(NO₃)₃ aqueoussolution and left incubating for about 16 hour. After this incubationperiod, a slow multistep addition was conducted with 550 μl of 0.2MCe(NO₃)₃ aqueous solution, 950 μl of 0.2M La(NO₃)₃ aqueous solution and1500 μl of 0.4M NH₄OH. This addition was conducted in 39 hours and 60steps. The reaction mixtures were left stirred for at least another 10hours at room temperature. After that time the suspensions werecentrifuged in order to separate the solid phase from the liquid phase.The precipitated material was then re-suspended in 4 ml of ethanol. Theethanol suspensions were centrifuged in order to finish removingun-reacted species. The gel-like product remaining was then dried for 1hours at 65° C. in an oven and then calcined in a muffle oven in air(load in the furnace at room temperature, ramp to 100° C. with 2° C./minrate, dwell for 30 min, ramp to 500° C. with 2° C./min rate, dwell for120 min, cool to room temperature).

Example 32 Synthesis of Pr₂O₃/La₂O₃ Mixed Oxide Nanowires

0.5 ml of 1M Pr(NO₃)₃ aqueous solution and 4.5 ml of 1M La(NO₃)₃ aqueoussolution were mixed with 40 ml deionized water. Once well mixed, 5 ml ofa 3M NH₄OH aqueous solution were quickly injected in the mixture. Aprecipitate immediately formed. The suspension was kept stirring foranother 10 minutes then transferred to centrifuge tubes and centrifugedin order to separate the solid phase from the liquid phase. Theprecipitated material was then re-suspended in 35 ml of deionized water.The solid fraction was separated again by centrifugation and the washingstep was repeated one more time. The gel-like product remaining was thendispersed in deionized water and the suspension volume adjusted to 20ml. The suspension was then transferred to a hydrothermal bomb andplaced in an oven at 120° C. for 2 hours. The solids obtained afterhydrothermal treatment were then separated by centrifugation and washedonce with 35 ml of deionized water. The washed hydrothermally treatedpowder was then dried at 120° C. for 16 hours. The surface area,determine by BET, of the dried powder was about 41 m²/g. Transmissionelectron microscopy was used to characterize the morphology of thissample further. The powder was constituted of large aspect ratioparticles with about 30 nm wide by 0.5 to 2 μm length. The powder wascalcined in three temperature steps at 200, 400 and 500° C. with 3°C./min ramp and 2 hours of dwell time at each step. The surface area ofthe Pr₂O₃/La₂O₃ mixed oxide nanowires was about 36 m²/g.

Example 33 Synthesis of MgO/Eu₂O₃ Core/Shell nanowires

In this example, Mg(OH)₂ nanowires are used as a support to grow a shellof Eu(OH)₃. Mg(OH)₂ nanowires, prepared according to the methodsdescribed in example 28 (wet product, before being dried) were used toprepare a suspension in deionized water with a concentration of 3 g/1 ofdried Mg(OH)₂. To 30 ml of the Mg(OH)₂ suspension, 3 ml of 0.1M Eu(NO₃)₃aqueous solution and 3 ml of 0.3M NH₄OH aqueous solution were added in aslow multistep addition. This addition was conducted in 48 hours and 360steps. The solids were then separated using centrifugation. The powderis washed with 30 ml DI water and centrifuged again. An aliquot isretrieved prior to calcination for transmission electron miscopyevaluation of the sample morphology. The sample is mainly constituted ofhigh aspect ratio wires with a rough surface. The general morphology ofthe support is preserved and no separate phase is observed.

The remaining of the powder was dried at 120° C. for 3 hours andcalcined in three steps at 200, 400 and 500° C. with 2 hours at eachstep and a ramp rate of 3° C./min. The surface area, determined by BET,of the MgO/Eu₂O₃ core/shell nanowires is 209 m²/g.

Example 34 Synthesis of Y₂O₃/La₂O₃ Mixed Oxide Nanowires

0.5 ml of 1M Y(NO₃)₃ aqueous solution and 4.5 ml of 1M La(NO₃)₃ aqueoussolution were mixed with 40 ml deionized water. Once well mixed, 5 ml ofa 3M NH4OH aqueous solution was quickly injected in the mixture. Aprecipitate immediately forms. The suspension was kept stirring foranother 10 minutes then transferred to centrifuge tubes and centrifugedin order to separate the solid phase from the liquid phase. Theprecipitated material was then re-suspended in 35 ml deionized water.The solid fraction was separated again by centrifugation and the washingstep was repeated one more time. The gel-like product remaining was thendispersed in deionized water and the suspension volume adjusted to 20ml. The suspension was then transferred to a hydrothermal bomb andplaced in an oven at 120° C. for 2 hours. The solids obtained afterhydrothermal treatment were then separated by centrifugation and washedonce with 35 ml of deionized water. The washed hydrothermally treatedpowder was then dried at 120° C. for 16 hours. The surface area,determined by BET, of the dried powder is about 20 m2/g. Transmissionelectron microscopy was used to characterize the morphology of thissample further. The powder was constituted of large aspect ratioparticles with about 20 to 40 nm wide by 0.5 to 2 micron length. TheY₂O₃/La₂O₃ mixed oxide nanowires ware calcined in three temperaturesteps at 200, 400 and 500° C. with 3° C./min ramp and 2 hours of dwelltime at each step.

Example 35 Synthesis of La₂O₃ Nanowires

1 g of La₂O₃ (13.1 mmol) and 0.92 g of NH₄Cl (18.6 mmol) were placed ina 25 ml stainless steel autoclave with a Teflon liner (Parr Bomb No.4749). 10 ml deionized water were then added to the dry reactants. Theautoclave was sealed and placed in a 160° C. oven for 12 h. After 12 h,the autoclave was allowed to cool. The nanowires were washed severaltimes with 10 mL of water to remove any excess NH₄Cl. The product wasthen dried in an oven for 15 hours at 65° C. in an oven and thencalcined in a muffle oven in air (load in the furnace at roomtemperature, ramp to 100° C. with 2° C./min rate, dwell for 30 min, rampto 400° C. with 2° C./min rate, dwell for 240 min, ramp to 550° C. with2° C./min rate, dwell for 240 min, cool to room temperature.)

Example 36 Synthesis of La₂O₃/Nd₂O₃ Mixed Oxide Nanowires

0.5 g of La₂O₃ (1.5 mmol), 0.52 g of Nd₂O₃ (1.5 mmol), and 0.325 g ofNH₄Cl (6 mmol) were ground together using a mortar and pestle. Once thedry reactants were well mixed, the ground powder was placed in a ceramiccrucible and then the crucible was transferred to a tube furnace. Thetube furnace atmosphere was flushed with nitrogen for 0.5 h. Thereactants were then calcined under nitrogen (25° C.-450° C., 2° C./minramp, dwell 1 h; 450° C.-900° C.; 2° C./min ramp, 1 h hold, cool to roomtemperature.) The product (0.2 g) was placed in 10 mL of deionized waterand stirred at room temperature for 24 h. The nanowires were then washedseveral times with deionized H₂O and dried in an oven for 15 hours at65° C. in an oven and then calcined in a muffle oven in air (load in thefurnace at room temperature, ramp to 100° C. with 2° C./min rate, dwellfor 30 min, ramp to 400° C. with 2° C./min rate, dwell for 240 min, rampto 550° C. with 2° C./min rate, dwell for 240 min, cool to roomtemperature.)

Example 37 Oligomerization of Ethylene to Liquid Hydrocarbon Fuels withHigh Aromatics Content

0.1 g of the zeolite ZSM-5 is loaded into a fixed bed micro-reactor andheated at 400° C. for 2 h under nitrogen to activate the catalyst. TheOCM effluent, containing ethylene and ethane, is reacted over thecatalyst at 400° C. at a flow rate of 50 mL/min and GSHV=3000-10000mL/(g h). The reaction products are separated into liquid and gascomponents using a cold trap. The gas and liquid components are analyzedby gas chromatography. C5-C10 hydrocarbon liquid fractions, such asxylene and isomers thereof, represent 90% of the liquid product ratiowhile the C₁₁-C₁₅ hydrocarbon fraction represents the remaining 10% ofthe product ratio.

Example 38 Oligomerization of Ethylene to Liquid Hydrocarbon Fuels withHigh Olefins Content

0.1 g of the zeolite ZSM-5 doped with nickel is loaded into a fixed bedmicro-reactor and heated at 350° C. for 2 h under nitrogen to activatethe catalyst. The OCM effluent, containing ethylene and ethane, isreacted over the catalyst at 250-400° C. temperature rage withGSHV=1000-10000 mL/(g h). The reaction products are separated intoliquid and gas components using a cold trap. The gas and liquidcomponents are analyzed by gas chromatography. C₄-C₁₀ olefin hydrocarbonliquid fractions, such as butene, hexane and octene represent 95% of theliquid product ratio while the C₁₂-C₁₈ hydrocarbon fraction representsthe remaining 5% of the product ratio. Some trace amounts of oddnumbered olefins are also possible in the product.

Example 39 Synthesis of MnWO₄ Nanowires

0.379 g of Na₂WO₄ (0.001 mol) was dissolved in 5 mL of deionized water.0.197 g of MnCl₂.6H₂O (0.001 mol) was dissolved in 2 mL of deionizedwater. The two solutions were then mixed and a precipitate was observedimmediately. The mixture was placed in a stainless steel autoclave witha Teflon liner (Parr Bomb No. 4749). 40 ml of deionized water was addedto the reaction mixture and the pH was adjusted to 9.4 with NH4OH. Theautoclave was sealed and placed in a 120° C. oven. The reaction was leftto react for 18 h and then it was cooled to room temperature. Theproduct was washed with deionized water and then dried in a 65° C. oven.The samples were calcined in a muffle oven in air (load in the furnaceat room temperature, ramp to 400° C. with 5° C./min rate, dwell for 2 h,ramp to 850° C. with 5° C./min rate, dwell for 8 h, cool to roomtemperature).

Example 40 Preparation of Supported MnWO₄ Nanowire Catalysts

Supported MnWO₄ nanowires catalysts are prepared using the followinggeneral protocol. MnWO₄ nanowires are prepared using the methoddescribed in example 42. Manganese tungstate nanowires, support, andwater are slurried for 6 h at room temperature. The manganese tungstateto support ratio is 2-10 wt %. The mixture is dried in a 65° C. oven andthen calcined in a muffle oven in air: load in the furnace at roomtemperature, ramp to 400° C. with 5° C./min rate, dwell for 2 h, ramp to850° C. with 5° C./min rate, dwell for 8 h, cool to room temperature.The following is a list of exemplary supports that may be used: SiO₂,Al₂O₃, SiO₂—Al₂O₃, ZrO₂, TiO₂, HfO₂, Silica-Aluminum Phosphate, andAluminum Phosphate.

Example 41 OCM Catalyzed by La₂O₃ Nanowires

50 mg of La₂O₃ nanowires catalyst, prepared using the method describedin example 19, were placed into a reactor tube (4 mm ID diameter quartztube with a 0.5 mm ID capillary downstream), which was then tested in anAltamira Benchcat 203. The gas flows were held constant at 46 sccmmethane and 54 sccm air, which correspond to a CH4/O2 ratio of 4 and afeed gas-hour space velocity (GHSV) of about 130000 h⁻¹. The reactortemperature was varied from 400° C. to 500° C. in a 100° C. incrementand from 500° C. to 850° C. in 50° C. increments. The vent gases wereanalyzed with gas chromatography (GC) at each temperature level.

FIG. 24 shows the onset of OCM between 500° C. and 550° C. The C2selectivity, methane conversion and C2 yield at 650° C. were 54%, 27%and 14%, respectively.

The various embodiments described above can be combined to providefurther embodiments. All of the U.S. patents, U.S. patent applicationpublications, U.S. patent applications, foreign patents, foreign patentapplications and non-patent publications referred to in thisspecification and/or listed in the Application Data Sheet, areincorporated herein by reference, in their entirety. Aspects of theembodiments can be modified, if necessary to employ concepts of thevarious patents, applications and publications to provide yet furtherembodiments. These and other changes can be made to the embodiments inlight of the above-detailed description. In general, in the followingclaims, the terms used should not be construed to limit the claims tothe specific embodiments disclosed in the specification and the claims,but should be construed to include all possible embodiments along withthe full scope of equivalents to which such claims are entitled.Accordingly, the claims are not limited by the disclosure.

The invention claimed is:
 1. A method for the preparation of ethylenefrom methane, the method comprising contacting a mixture comprisingoxygen and methane at a temperature below 600° C. with a catalyticnanowire, thereby producing C2 hydrocarbons at a selectivity of greaterthan 30%, wherein the catalytic nanowire is an inorganic catalyticpolycrystalline nanowire having a ratio of effective length to actuallength of less than one and an aspect ratio of greater than ten asmeasured by TEM in bright field mode at 5 keV, wherein the catalyticnanowire comprises one or more elements from any of Groups 1 through 7,lanthanides, actinides or combinations thereof in the form of oxides,hydroxides, oxyhydroxides, sulfates, carbonates, oxide carbonates,oxalates, phosphates, hydrogenphosphates, dihydrogenphosphates,oxyhalides, hydroxihalides, oxysulfates or combinations thereof.
 2. Amethod for preparing a downstream product of ethylene, the methodcomprising converting ethylene into a downstream product of ethylene,and the method comprising contacting a mixture comprising oxygen andmethane at a temperature below 600° C. with a catalytic nanowire,thereby producing C2 hydrocarbons at a selectivity of greater than 30%,wherein the catalytic nanowire is an inorganic catalytic polycrystallinenanowire having a ratio of effective length to actual length of lessthan one and an aspect ratio of greater than ten as measured by TEM inbright field mode at 5 keV, wherein the catalytic nanowire comprises oneor more elements from any of Groups 1 through 7, lanthanides, actinidesor combinations thereof in the form of oxides, hydroxides,oxyhydroxides, sulfates, carbonates, oxide carbonates, oxalates,phosphates, hydrogenphosphates, dihydrogenphosphates, oxyhalides,hydroxihalides, oxysulfates or combinations thereof.
 3. A method for thepreparation of a downstream product of ethylene, the method comprising:converting methane into ethylene by contacting a mixture comprisingoxygen and methane at a temperature below 600° C. with a catalyticnanowire, thereby producing C2 hydrocarbons at a selectivity of greaterthan 30%; and oligomerizing the ethylene to prepare a downstream productof ethylene, wherein the catalytic nanowire is an inorganic catalyticpolycrystalline nanowire having a ratio of effective length to actuallength of less than one and an aspect ratio of greater than ten asmeasured by TEM in bright field mode at 5 keV, wherein the catalyticnanowire comprises one or more elements from any of Groups 1 through 7,lanthanides, actinides or combinations thereof in the form of oxides,hydroxides, oxyhydroxides, sulfates, carbonates, oxide carbonates,oxalates, phosphates, hydrogenphosphates, dihydrogenphosphates,oxyhalides, hydroxihalides, oxysulfates or combinations thereof.
 4. Themethod of claim 1, wherein the one or more elements are in the form ofoxides.
 5. The method of claim 1, wherein the one or more elements arein the form of hydroxides.
 6. The method of claim 1, wherein thecatalytic nanowire comprises Mg, Ca, La, W, Mn, Mo, Nd, Sm, Eu, Pr, Zror combinations thereof.
 7. The method of claim 1, wherein the catalyticnanowire comprises MgO, CaO, La₂O₃, Na₂WO₄, Mn₂O₃, Mn₃O₄, Nd₂O₃, Sm₂O₃,Eu₂O₃, Pr₂O₃, Mg₆MnO₈, NaMnO₄, Na/Mn/W/O, MnWO₄ or combinations thereof.8. The method of claim 1, wherein the catalytic nanowire furthercomprises one or more dopants comprising metal elements, semi-metalelements, non-metal elements or combinations thereof.
 9. The method ofclaim 8, wherein the dopant comprises Li, Na, K, Mg, Ca, Ba, Sr, Eu, Sm,Co or Mn.
 10. The method of claim 9, wherein the catalytic nanowirecomprises Li/MgO, Ba/MgO, Sr/La₂O₃, Mg/Na/La₂O₃, Sr/Nd₂O₃, or Mn/Na₂WO₄.11. The method of claim 8, wherein the atomic ratio of the one or moreelements from Groups 1 through 7, lanthanides or actinides to the dopantranges from 1:1 to 10,000:1.
 12. The method of claim 1, wherein thecatalytic nanowire comprises a combination of two or more compoundscomprising the one or more elements.
 13. The method of claim 12, whereinthe catalytic nanowire comprises Mn₂O₃/Na₂WO₄,Mn₃O₄/Na₂WO₄MnWO₄/Na₂WO₄/Mn₂O₃, MnWO₄/Na₂WO₄/Mn₃O₄ or NaMnO₄/MgO. 14.The method of claim 1, wherein the catalytic nanowire has a diameter ofbetween 7 nm and 200 nm as determined by TEM in bright field mode at 5keV.
 15. The method of claim 1, wherein the catalytic nanowire has anactual length of between 100 nm and 10 μm as determined by TEM in brightfield mode at 5 keV.
 16. The method of claim 1, wherein the catalyticnanowire has a ratio of effective length to actual length of less than0.8.
 17. The method of claim 1, wherein the powder x-ray diffractionpattern of the nanowire shows an average crystalline domain size of lessthan 50 nm.
 18. The method of claim 1, wherein the catalytic nanowirefurther comprises a support material.
 19. The method of claim 18,wherein the support material comprises an inorganic oxide, Al₂O₃, SiO₂,TiO₂, MgO, ZrO₂, HfO₂, CaO, ZnO, LiAlO₂, MgAl₂O₄, MnO, MnO₂, Mn₂O₄,Mn₃O₄, La₂O₃, activated carbon, silica gel, zeolites, activated clays,activated Al₂O₃, diatomaceous earth, magnesia, aluminosilicates, calciumaluminate, support nanowires or combinations thereof.
 20. The method ofclaim 1, wherein the catalytic nanowire comprises an inner core and anouter layer, the inner core and outer layer each independentlycomprising one or more elements selected from Groups 1 through 7,lanthanides and actinides.
 21. The method of claim 1, wherein theethylene is prepared from methane via the oxidative coupling of methane(OCM) reaction.
 22. The method of claim 1, wherein the mixturecomprising oxygen and methane comprises air.
 23. The method of claim 2,wherein the one or more elements are in the form of oxides.
 24. Themethod of claim 2, wherein the one or more elements are in the form ofhydroxides.
 25. The method of claim 2, wherein the catalytic nanowirecomprises Mg, Ca, La, W, Mn, Mo, Nd, Sm, Eu, Pr, Zr or combinationsthereof.
 26. The method of claim 2, wherein the catalytic nanowirecomprises MgO, CaO, La₂O₃, Na₂WO₄, Mn₂O₃, Mn₃O₄, Nd₂O₃, Sm₂O₃, Eu₂O₃,Pr₂O₃, Mg₆MnO₈, NaMnO₄, Na/Mn/W/O, MnWO₄ or combinations thereof. 27.The method of claim 2, wherein the catalytic nanowire further comprisesone or more dopants comprising metal elements, semi-metal elements,non-metal elements or combinations thereof.
 28. The method of claim 27,wherein the dopant comprises Li, Na, K, Mg, Ca, Ba, Sr, Eu, Sm, Co orMn.
 29. The method of claim 28, wherein the catalytic nanowire comprisesLi/MgO, Ba/MgO, Sr/La₂O₃, Mg/Na/La₂O₃, Sr/Nd₂O₃, or Mn/Na₂WO₄.
 30. Themethod of claim 27, wherein the atomic ratio of the one or more elementsfrom Groups 1 through 7, lanthanides or actinides to the dopant rangesfrom 1:1 to 10,000:1.
 31. The method of claim 2, wherein the catalyticnanowire comprises a combination of two or more compounds comprising theone or more elements.
 32. The method of claim 31, wherein the catalyticnanowire comprises Mn₂O₃/Na₂WO₄, Mn₃O₄/Na₂WO₄MnWO₄/Na₂WO₄/Mn₂O₃,MnWO₄/Na₂WO₄/Mn₃O₄ or NaMnO₄/MgO.
 33. The method of claim 2, wherein thecatalytic nanowire has a diameter of between 7 nm and 200 nm asdetermined by TEM in bright field mode at 5 keV.
 34. The method of claim2, wherein the catalytic nanowire has an actual length of between 100 nmand 10 μm as determined by TEM in bright field mode at 5 keV.
 35. Themethod of claim 2, wherein the catalytic nanowire has a ratio ofeffective length to actual length of less than 0.8.
 36. The method ofclaim 2, wherein the powder x-ray diffraction pattern of the catalyticnanowire shows an average crystalline domain size of less than 50 nm.37. The method of claim 2, wherein the catalytic nanowire furthercomprises a support material.
 38. The method of claim 37, wherein thesupport material comprises an inorganic oxide, Al₂O₃, SiO₂, TiO₂, MgO,ZrO₂, HfO₂, CaO, ZnO, LiAlO₂, MgAl₂O₄, MnO, MnO₂, Mn₂O₄, Mn₃O₄, La₂O₃,activated carbon, silica gel, zeolites, activated clays, activatedAl₂O₃, diatomaceous earth, magnesia, aluminosilicates, calciumaluminate, support nanowires or combinations thereof.
 39. The method ofclaim 2, wherein the catalytic nanowire comprises an inner core and anouter layer, the inner core and outer layer each independentlycomprising one or more elements selected from Groups 1 through 7,lanthanides and actinides.
 40. The method of claim 2, wherein theethylene has been prepared via the oxidative coupling of methane (OCM)reaction.
 41. The method of claim 40, wherein the oxidative coupling ofmethane reaction is performed in the presence of air.
 42. The method ofclaim 2, wherein the downstream product of ethylene is natural gasoline.43. The method of claim 2, wherein the downstream product of ethylenecomprises 1-hexene, 1-octene or combinations thereof.
 44. The method ofclaim 3, wherein the one or more elements are in the form of oxides. 45.The method of claim 3, wherein the one or more elements are in the formof hydroxides.
 46. The method of claim 3, wherein the catalytic nanowirecomprises Mg, Ca, La, W, Mn, Mo, Nd, Sm, Eu, Pr, Zr or combinationsthereof.
 47. The method of claim 3, wherein the catalytic nanowirecomprises MgO, CaO, La₂O₃, Na₂WO₄, Mn₂O₃, Mn₃O₄, Nd₂O₃, Sm₂O₃, Eu₂O₃,Pr₂O₃, Mg₆MnO₈, NaMnO₄, Na/Mn/W/O, MnWO₄ or combinations thereof. 48.The method of claim 3, wherein the catalytic nanowire further comprisesone or more dopants comprising metal elements, semi-metal elements,non-metal elements or combinations thereof.
 49. The method of claim 48,wherein the dopant comprises Li, Na, K, Mg, Ca, Ba, Sr, Eu, Sm, Co orMn.
 50. The method of claim 49, wherein the catalytic nanowire comprisesLi/MgO, Ba/MgO, Sr/La₂O₃, Mg/Na/La₂O₃, Sr/Nd2O3, or Mn/Na₂WO₄.
 51. Themethod of claim 48, wherein the atomic ratio of the one or more elementsfrom Groups 1 through 7, lanthanides or actinides to the dopant rangesfrom 1:1 to 10,000:1.
 52. The method of claim 3, wherein the catalyticnanowire comprises a combination of two or more compounds comprising theone or more elements.
 53. The method of claim 52, wherein the catalyticnanowire comprises Mn₂O₃/Na₂WO₄, Mn₃O₄/Na₂WO₄MnWO₄/Na₂WO₄/Mn₂O₃,MnWO₄/Na₂WO₄/Mn₃O₄ or NaMnO₄/MgO.
 54. The method of claim 3, wherein thecatalytic nanowire has a diameter of between 7 nm and 200 nm asdetermined by TEM in bright field mode at 5 keV.
 55. The method of claim3, wherein the catalytic nanowire has an actual length of between 100 nmand 10 μm as determined by TEM in bright field mode at 5 keV.
 56. Themethod of claim 3, wherein the catalytic nanowire has a ratio ofeffective length to actual length of less than 0.8.
 57. The method ofclaim 3, wherein the powder x-ray diffraction pattern of the catalyticnanowire shows an average crystalline domain size of less than 50 nm.58. The method of claim 3, wherein the catalytic nanowire furthercomprises a support material.
 59. The method of claim 58, wherein thesupport material comprises an inorganic oxide, Al₂O₃, SiO₂, TiO₂, MgO,ZrO₂, HfO₂, CaO, ZnO, LiAlO₂, MgAl₂O₄, MnO, MnO₂, Mn₂O₄, Mn₃O₄, La₂O₃,activated carbon, silica gel, zeolites, activated clays, activatedAl₂O₃, diatomaceous earth, magnesia, aluminosilicates, calciumaluminate, support nanowires or combinations thereof.
 60. The method ofclaim 3, wherein the catalytic nanowire comprises an inner core and anouter layer, the inner core and outer layer each independentlycomprising one or more elements selected from Groups 1 through 7,lanthanides and actinides.
 61. The method of claim 3, wherein themethane is converted into ethylene via the oxidative coupling of methane(OCM) reaction.
 62. The method of claim 61, wherein the oxidativecoupling of methane reaction is performed in the presence of air. 63.The method of claim 3, wherein the downstream product of ethylene isnatural gasoline.
 64. The method of claim 3, wherein the downstreamproduct of ethylene comprises 1-hexene, 1-octene or combinationsthereof.
 65. The method of claim 1, wherein the temperature ranges from550° C. to below 600° C.
 66. The method of claim 2, wherein thetemperature ranges from 550° C. to below 600° C.
 67. The method of claim3, wherein the temperature ranges from 550° C. to below 600° C.
 68. Themethod of claim 1, wherein the temperature ranges from 500° C. to 550°C.
 69. The method of claim 2, wherein the temperature ranges from 500°C. to 550° C.
 70. The method of claim 3, wherein the temperature rangesfrom 500° C. to 550° C.